Chaka filed a petition for appointment of guardianship last week -- claiming she has already "assumed on a day-to-day basis the role of the child's parent fulfilling both the child's physical and psychological needs for care and affection."

Chaka claims the child's mother -- who lives in the same house -- is incapable of caring for the girl because of a "heavy involvement in drugs."

Chaka's sister Tammy McCrary -- who was also awarded custody -- filed an additional statement in the petition, claiming Chaka's son "also uses and abuses drugs and other illegal substances."