What would you do if you were this mother?

You're in the process of divorcing the father of your 2 children, a boy 10 and a girl 5. The divorce is taking a long time because you can't agree on anything. The custody arrangement is that he has them every other weekend. The little girl has done things that indicate sexual abuse, like barricading herself in her bed with all of her toys when she sleeps at the father's house and according to her therapist having 'sexualized' behaviors and the girl and her brother both say the father took a bath with her and the girl told you that what happened in the bathtub is a 'secret.' And you strongly think she's being abused everytime she goes there but the judge won't change the arrangement because there's no proof. You live in a state where the only evidence allowed would be if the girl disclosed herself what is going on - the mother or therapist can't say what they know. It has to come from the child and the child won't directly tell anyone. What would you do if you were the mother?

The girl either by acting it out in play therapy or by directly telling her, actually has told the therapist what is going on and the therapist even videotaped the girl's disclosures but CPS would not even look at it and for some reason I don't understand the judge who is deciding custody can't use it either.