Child custody in abuse case?

Well I have a friend that suspects her niece is being abused, in that the her custodian hits her and makes her do all the work around the house. I have told her to go to the police and the right agencies. But there lies the problem. She ( the lil girl), her( my friend) and I don't want the state to take the lil girl we want to keep her in the family. Well my friend would like custody of her. But she lives with her boyfriend. Now the lil girl does not live with her parents, her grandparents got custody of her, and the grandma is doing the abusing. The grandpa doesn't like her. What should we do. Can my friend get custody of the girl. Don't worry in the mean time we have the grandparents scared cuz I told them if I see another bruise on that girl there will be hell to pay. P. S. The lil girl is scared of what might happen in the mean time