It is extremely difficult for us to find the name of Devi Radharani's name in the Srimad Bhagvatam, how can this be when she was the foremost of the Gopis who were with Krishna. This even led an argument between Gaudiya Vaishnavite Acharyas and Acharyas from other sects where the latter argued that Srimati Radharani should not be worshipped together with Krishna as her name is not found in the Srimad Bhagvatam.
But Gaudiya Vaishnava Acharyas have revealed that the word 'Radha' can be found in
bhagavan harir isvarah
yan no vihaya govindah
prito yam anayad rahah
Here in the word aradhita, the name Radha has been derived. However, the name of Radharani is directly mentioned in other Puranas. So why be so conservative in mentioning Devi's name in one of the most important scriptures talking about the history of Sri Krishna?
The Vedic seers, however, deal in indirect terms as I am pleased by such indirect descriptions.
Hence, Shukadeva indirectly refers to Radha by using common nouns such as ‘Kaachit’ (One Girl), ‘Saa Vadhuh’ (That Bride (of Krishna)), and ‘Priya’, (Beloved), 'anayārādhito nūnaṁ'.
Gopis being the best of devotees, Shukadeva expressed them indirectly as per Lord's desire. Very confidential things are sometimes expressed indirectly.
However, using the hints of Bhagavata Purana and linking it with other descriptions found in other puranas, Gaudiya Vaishnava acharyas identify even the names of the specific gopi and their respective verses who offered prayers as well in the Gopi Gita.
Shukadeva himself would not have gone into details so that he could complete Bhagavata recitation.
SB 10.12.44 — Sūta Gosvāmī said: O Śaunaka, greatest of saints and devotees, when Mahārāja Parīkṣit inquired from Śukadeva Gosvāmī in this way, Śukadeva Gosvāmī, immediately remembering subject matters about Kṛṣṇa within the core of his heart, externally lost contact with the actions of his senses. Thereafter, with great difficulty, he revived his external sensory perception and began to speak to Mahārāja Parīkṣit about kṛṣṇa-kathā.
The gopis are considered the best of the devotees by Uddhava himself who is glorified in the below verses.
SB 3.4.31 — Uddhava is not inferior to Me in any way because he is never affected by the modes of material nature. Therefore he may remain in this world in order to disseminate specific knowledge of the Personality of Godhead.
SB 11.16.29 — Among those entitled to the name Bhagavān I am Vāsudeva, and indeed, you, Uddhava, represent Me among the devotees. I am Hanumān among the Kimpuruṣas, and among the Vidyādharas I am Sudarśana.
Such Uddhava longed for the sweetness of the love that gopis had for Krishna.
SB 10.47.58 — [Uddhava sang:] Among all persons on earth, these cowherd women alone have actually perfected their embodied lives, for they have achieved the perfection of unalloyed love for Lord Govinda. Their pure love is hankered after by those who fear material existence, by great sages, and by ourselves as well. For one who has tasted the narrations of the infinite Lord, what is the use of taking birth as a high-class brāhmaṇa, or even as Lord Brahmā himself?
So, if he would have gone into details, it could have invited more questions from Parikshit and Shukadeva could have lost external consciousness again he would not have been able to complete Bhagavata recitation in 7 days.
Radha has been perceived differently by different people down the ages. She is sometimes the adulterous and amorous lover of Krishna and at others his divine consort. This perhaps makes her the most confusing character in Indian mythology.
In the eastern religious tradition, she is however accepted as a beloved of Lord Krishna but the wife of another, sometimes mentioned by name as Aiyyan.
Anyway, Krishna without Radha is unthinkable, and I consider the view accepted by general tradition as appropriate
Krishna went to his mother, Yashoda, and turned on the full force of his charm. "Mother," he said, "I want you to send a message to Radha's family, asking for her hand in marriage." Yashoda thought this was another of Krishna's pranks. But when Krishna persisted she replied firmly and clearly.
She said, " You cannot marry Radha for several reasons. She is engaged to Aiyyan. You are the son of a chief and her family is much lower in status. She is older than you. And she is a brazen girl, totally unfit to be a wife."
Krishna then used his final weapon. He threatened that his mother would not only lose a lovely daughter-in-law if she refused, but also her son. Yashoda then asked him to settle the matter with his father. So Krishna went to Nand and repeated his request. His father said with a wink, "I have noticed that you are spending more and more time with the girls lately. No wonder you want one for yourself. There are many chieftains who would willingly wed their daughters to you." Krishna interrupted and said that he wanted to marry Radha and not a chieftain's daughter. The arguments were repeated. Finally Nand said he was no match for Krishna in a debate. Their family priest, Sage Garg, was arriving the next day and Nand would refer the matter to him.
Krishna told Sage Garg that since he and Radha desired each other, they should get married. Garg replied that desire as a reason for mating is the way of animals. The matching of temperaments, family backgrounds and future plans should be considered while selecting a spouse. Krishna stated that even as per these considerations he could not find any fault with his choice. Radha's temperament was perfectly matched to his, their family backgrounds were similar and both of them would be spending the rest of their lives in Vrindavan doing what the men and women of Vrindavan had always been doing.
Sage Garg then said, "I think it is time to tell you the truth about your birth. You are the eighth son of Prince Vasudev and Devaki. It was prophesied that you would kill your maternal uncle Kansa and deliver the Yadava race from his tyranny. Hence you were secretly brought to Gokul and were brought up as the son of Nand and Yashoda. The great sage Vyasa has foretold that you will be the leader of the Yadava race and the saviour of all humanity. Hence I have brought Sage Sandipani with me, who is to begin your education in the scriptures, procedures of governance and the art of warfare. We all have great expectations of you. Radha is a village girl. She will not be a suitable companion in this endeavour. That is why we are against this marriage."
Krishna quietly digested what had been said and then replied softly but firmly. "First of all I would like to aver that Nand and Yashoda are my parents and I will always look upon them as such. Then I would request you to keep the story of my birth a secret from the people of Vrindavan till it is time for me to leave. If they learn the truth then their attitude towards me will change and this I will not be able to bear. You say that I am to deliver all humanity from suffering. I cannot begin this formidable task by thrusting the person who loves me the most into unbearable suffering.
From the moment Radha saw me tied to the mortar eight years ago, there has not been a single day that she has not waited for me. With every breath that she has drawn she has taken my name. For her spring comes when I come to meet her and winter begins when I leave her. If I had died fighting Kaliya, the poisonous snake, many in Vrindavan would have been heart broken. Mother would have never stopped crying and father would have lost his smile forever. But Radha would have given up her life there and then. Radha lives for me and in me and I live for her and in her. If you prevent this marriage, you will be depriving me of the right and power to carry out the great tasks you want me to. I beseech you with folded hands to grant your consent."
Sage Garg was overcome by the rationality and intensity of this speech. He gave his consent. Radha's joy knew no bound. And in the celebrations that followed Aiyyan was forgotten.
The news that Krishna was leaving spread like wildfire throughout Vrindavan. The youth sensed that they were losing a staunch friend; the maidens sensed that they were losing a man of their dreams and Radha....
Before Radha could even begin to ponder upon the consequences, the melodious sound of a flute wafted throughout the village. The women left what they were doing and ran to the Madhuban. There was no time to wear their ornaments or comb their hair. While running they tried to arrange their clothes to give an appearance of modesty but soon gave up. Radha picked up her anklets and raced ahead of everyone else, her bosom heaving with excitement. Her Kahn was calling her. Krishna was standing in his usual spot, his right leg crossed over his left, and playing his flute with gay abandon. Radha cuddled up to him and began to sway in the rhythm of his music. The other maidens formed circles around them and began to dance. The men folk, the elders and children too had come there, but were watching from a distance, so as not to embarrass the dancers.
Every maiden wanted Krishna to dance only with her, every maiden imagined that Krishna was dancing only with her and the spectators could see a multitude of Krishnas, each dancing separately with one of the lasses. Such is the power of love; such is the power of faith. This was the Maharasa or the "great dance". When the dancing stopped Krishna and Radha were missing.
Radha and Krishna were heading for their favourite nook in the Madhuban, near the Yamuna river. Radha was in Krishna's arms, her tousled head resting on his shoulder.
"Will you always be like this, Kahn?" asked Radha.
"Always," he replied, "Till the sun and the moon endure."
But Radha was not satisfied by this assurance. "Will you always remember me?" she asked.
"How can I forget you," replied Krishna, "You are my Goddess of beauty and joy."
They reached their destination and huddled close together on the mossy grass. They kissed tentatively at first, but the pent-up passions soon engulfed them and they united in body and soul. After a while Radha got up and began to tie her disheveled tresses into a knot. "Will we always be together after we are married," she inquired uncertainly. Krishna replied that they were inseparable and that they had just got married according to the Gandharva tradition. According to the this tradition, sexual intercourse among consenting couples was tantamount to the marriage rituals provided the male was of royal descent.
"You will always be my prince," said Radha, "but you are not of royal blood. And I do not regret our love making so you do not have to justify it." Then Krishna narrated the story of his birth, of his being the redeemer and his leaving for Mathura before dawn. Radha let the whole narration sink in and appeared to be forming some decisions of her own. "Is there anything that can make you stay?" she asked.
"Nothing can hold me from my destiny and my duty." Replied Krishna firmly. "Why do you worry? Are you afraid that I will die at Kansa's hands? It will be over soon and then I will call you to Mathura"
"No, I am sure that you will kill Kansa. And then you will become the king of the Yadavas. A lot of people will look up to you, will bow down before you, and will depend on you. You will become the saviour of humanity," said Radha.
"And you will be my queen, by my side always," added Krishna.
"No," replied Radha surely. "I am a poor cowherd girl. I will be lost in the palace intrigues. There will be many princesses wooing you and wanting you at any cost. I will be awkward and gawky compared to them. This village girl will be a handicap to you in your new avatar. For you will undeniably change. Your life will be filled with politics and manipulations. You will fight wars and participate in destruction. That will be a part of your destiny and I don't pass judgment. But the Kahn I loved was a cowherd boy, whose calling in life was to graze cattle, who played the flute and danced in the woods and whose crown was a peacock feather and weapon was a bamboo staff. I will not be able to see you in any other form." Radha was now sobbing convulsively and Krishna has to take her in his arms to calm her down.
After regaining her composure Radha continued. "Please listen to me Kahn! Let me stay here and take care of your parents. Here in Vrindavan I will see you in the waters of the Yamuna, the slopes of Govardhan and the trees of Madhuban and hence I will always be with the Kahn I knew."
They sat silently for a while reflecting on the past, savouring the last moments of togetherness and coming to terms with the future. Krishna broke the silence. "You are right Radha. In Mathura I will have to change and if you come with me then you will have to change as well. I will not be the Krishna you knew and you will not be the Radha I knew. We will not be able to replicate the magic we weaved here. And without either of us here, Vrindavan too will wither away. But if you stay back, then Vrindavan will become an enduring shrine to our love and you will be its deity." Krishna then told Radha that preparations had been made for them to get married in the Vedic manner and since the auspicious moment was drawing near they should return. Radha requested that Krishna leave his flute behind as a gift to her and Krishna readily agreed.
It was time for the final parting. The villagers had turned out to personally meet Krishna. Radha stood beside her mother in law, dressed in bridal finery, her face covered modestly by her sari. From time to time she looked up at Krishna, each glance a pledge of eternal devotion. Krishna's eyes met Radha's each time and he smiled at her reassuringly. Any other communication in front of the elders would be out of place. So no words were said and no hands touched. Krishna touched his mother's feet and mounted the bullock cart with Nand, Balaram and Akrura. Radha looked without blinking at the cart till it disappeared round the corner and then fainted. Krishna never set foot in Vrindavan again.
Krishna never set foot in Vrindavan again. But legend has it that he did come face to face with Radha once, later … much later. After he had killed Kansa and become the leader of the Yadavas. After he had shifted his capital from Mathura to Dwarka. After he had married Rukmini and Satyabhama and the others.
It was at the occasion of a total solar eclipse. A massive congregation had gathered at the field of Kurukshetra to bathe in the holy tank of Syamantapanchaka after the eclipse. (It was said that a dip in this tank after eclipses purified the soul. It was here that the great sage Parshurama had come to atone for killing the evil kings and warriors. He established that all killing is sinful, even when the persons killed are evil and deserve to die, even killing in war. Hence all killings have to be atoned for.) All the major kingdoms were represented. Krishna was leading the Yadavas. Dhritarashtra of Hastinapur was there with his sons the Kauravas and nephews the Pandavas. So were many other kings. Little did they know that soon they would be engaged in a do or die battle on this very field some years later. Many common folk had come as well. Among them was the cowherd community of Vrindavan.
When Krishna's parents, Vasudev and Devaki learnt of this they wanted to meet Nand and Yashoda. They had never met Krishna's foster parents and wanted to thank them for taking care of their son in his formative years. The meeting was a very emotional one. Balaram met his old cronies and reminisced about old times.
But when Krishna came face to face with Radha no words were said. No hands stretched to meet each other, no smile played upon lips and no eyes sparkled with delight. Only a million thoughts flashed through each mind and a deluge of tears flowed from each pair of eyes. Radha had promised not to get involved with Krishna's later life and she intended to keep that promise. Krishna did not want to say or do something that would make things difficult for Radha. They stood staring stonily at each other till all the thoughts were exhausted and the eyes were dry. Though Krishna and Radha had been physically separated, they had been inseparable spiritually and would continue to be so till the end of the world. Radha had seen the splendour in which Krishna's wives lived and the joy he lavished on them. But she knew that his tears were for her alone and that each drop was more valuable than all the riches of the world. Krishna knew that Vrindavan would be enshrined forever because of Radha's sacrifice. Both were assured that they had taken the correct decision many years ago. Without saying anything they said everything and went their separate ways. They never saw each other again.
This link may not answer your question but it will help you.
Radha is most likely a later creation as a personification of devotional love towards Krishna. The Mahabharata, Harivamsa and Bhagavata do not mention her. If she was so important you would think that these texts would have some mention about her. She was probably a later creation as later writers expanded upon the childhood of Krishna and especially his love for the Gopis.
Like any library, Hinduism Stack Exchange shares great information, but does not offer personalized advice, and does not take the place of seeking such advice from any Acharya, Pundit, astrologer, Guru or other trustworthy Counselor.