Hi OP, sorry for not replying before. I read your post and didn't know what to say, but it's been on my mind. Firstly, sorry that you and your dd are going through this.
You clearly didn't make the referral lightly or motivated by spite. Given you genuinely thought it was a real possibility, I don't see that you had a lot of choice. It's not up to you to be the investigator and the one who reaches a decision on it - you put it in the hands of the experts and leave it to them.
While I haven't had the sexual abuse angle, I have been there with the psychological/emotional abuse. Of course you just want to protect your child from all harm. But my experience has been that there's very little you can do pre-emptively. It's a long process, and the parent does get the beneft of the doubt until it becomes quite clear that they are messing up. Contact may be pretty okay in early childhood, and become more problematic later on - by that stage, the child is more articulate and is in a better position to communicate what's going wrong.
Either the allegation of sexual abuse will be found substantiated, and contact won't be an issue or else it will be found not to be, and new contac arrangements will be put in place. All you can do is to try to make them work, and to be vigilant for when they don't work.
It is hard, but our dcs at least have someone close to them looking out for them - there are children in awful situations who don't even have that much.