The grandson of Brahma, Viśravas Brahma had four wives. Devavarṇinī, Puṣpotkaṭā, Vākā and Kaikasī. śūrpaṇakhā is the daughter of Kaikasī. Kumbhini (who is also known as Kumbhinasī) is the daughter of Viśravas Brahma and Puṣpotkaṭā. Their father is same but the mothers are different. In this way, they are related. They are half-sisters. They had many other siblings. Rāvaṇa, Kumbhakarṇa, Kubera etc., are famous among them.
From Chapter 8 of Upodghata Pada of Brahmānda Purana,
38-40: Viśravas married Devavarṇinī, the daughter of Brihaspati, Puṣpotkaṭā and Vākā, the daughters of Mālyavān, Kaikasī, the daughter of Mālin. Listen to his childrn begot of these. Devavarṇinī gave birth to Vaiśravaṇa the eldest son.
Kaikasī gave birth to Rāvaṇa, Kumbhakarṇa and śūrpaṇakhā, a daughter. Vibhīṣaṇa is the fourth among her children.
55-56 Mahodara, Prahasta, Mahāpārśva and Khara were the sons of Puṣpotkaṭā. She had a daughter (named) Kumbhinasī. Also Triśiras Dūṣaṇa and Vidyujjihva the Rākṣasā are remembered as the sons of Vākā. There was a daughter named Anupālikā.
The list of children of Viśravas Brahma is given here
These are classified as the group of Rakshasas with the name of Paulastyas(descendants of Pulastya). Specific characteristics of Kumbhinasī is not listed in the Brahmanda Purana. But the common character of Pulastyas is given.
- Thus these ten Rākṣasās, the descendants of Pulastya, were of very cruel activities. They were of very terrible pursuits ever since their birth. All of these were unassailable even to the devas.
But it is not clear whether Kumbhinasī is cruel or not.
The physical characteristics of Rakshasas(including paulastyas is given) is listed in the chapter.
63-69 They are tawny coloured and have round eyes. They have big bellies and huge bodies. They have eight curved fang like teeth and pikelike ears. Their hairs stand upright. Their mouths appear as though slit open upto the ears(on either side). Their smoke coloured hairs are like Munja grass. They have large thick heads shedding bright lustre. Their thighs and forearms are short. Their faces are copper-coloured. Their lips and tongues hang down. Their brows appear dangling. THeir noses are thick. They have blue(black) limbs with red necks. Their eyes are majestic and appear terrible. Their voice and tone are extremely terrible. Their calves are extremely hideous and rolled up. They are stout and have prominently protruding noses. They are firm and have sturdy bodies like rocks. They are cruel and terrible ever since their birth. Generally they are consistent in their activities.
They put on ornaments like ear rings, armlets and coronets. They bedeck themselves in diverse kind of ornaments. They wear many kinds of Garlands and use all types of fragrant scents and unguents. They are remembered as habitual eaters of cooked rice, flesh and even human flesh. Thus is remebered the similarity in forms and features of demons by learned men. They are unequalled in strength, intelligence and ability to fight using the deceptive power of māya.(black magic).
Above are the characteristics of the seven classes of Demons.