custody w/adopted child

I live in ohio. here's my problem. i have a friend who gave her child up for adoption when the child was 4. she is 15 now. she was adopted by her aunt and uncle, who have since divorced. as it turns out, adopted mom (aunt) is abusive from time to time and now biological grandparents (biological mom and adopted dad/uncle's parents) would like to take custody. adopted dad/uncle still has custody/visitation rights and since it is his parents who would like to take custody, is there something he can do? what is involved? does child have right to chose since she has known her biological family her whole life? can this be handled without a huge legal mess? please help.

No, it can't be handled without a big legal mess. Children don't choose where they're going to live. Why doesn't Dad file for custody? He's her father, after all. Otherwise, if she is being abused, the best solution is to call CPS and report the abuse.