We know that Goddess Parvati is worshiped in her child or Kumari form and in north India Kanya-pujan is done at the end of Navratri as a symbolic offering to the goddess. To some extent the Brahmacharini form of Nav Durga and Bal Tripura Sundari also show the goddess as an unmarried girl. But do we have any such mention in any scripture of Goddess Kali as a child or a young girl?
Indeed there is a Bala form of Bhadrakali (and not Kali).
Her description is found in Kerala Agams. Mostly Bhadrakali temples in Kerala worship her in Bala form as in that way it is easy to control her rage.
Her iconography in Kerala tantras is as follows-
Sitting in padmasana, the devi is adorned with anklets in feet. She has huge fang and yet sports a smile of a child. The mundamala adorns her neck, with moon as her diadem on her crown. Know the Dhala and Chakra to be in her upper left & right hands, and Kapala and Khadga in her lower Left and righht hands respectively as her Ayudhas.
Vigraha of Bala Bhadrakali
Some of the notable temples of Bala Bhadrakali are -
Pournami Kavu, Venganoor, Kerala
Erumpili, Kanyakumari, TN
Melparai, Eraniel, TN
Kaipuram pattanam, Kerala
Shri Bala Bhadrakali Kshetram, Perumkadavila, Kerala
Bhadrakali Kavu, Palakkad