Last week I had a social worker ask to look around. She saw my daughters room and told me it was a hazard to her health and it needs to be cleaned. Basically they'll continue checking in to make sure it's suitable. I tried explaining my daughters behaviour but all she said was it is my "duty of care".
Sending her to live with a hoarder may not close the case against you and could, in fact, heighten the investigation of YOUR parenting. Is it more suitable? Sounds similar.
Is ex-DH in the same jurisdiction?
Stop trying to "explain" things to them, OP. Anything you say can be used against you. Re: DD or other kids.
The point that you are missing is that YOU have a duty of care to not have a room filled with bugs and rotting food for your kid to sleep in. Under your roof or where you send her. See why dad's may not fix the problem? Take everything out but the bed and a nightstand and give her an outfit a day. Do not allow food in the bedrooms. Lock the door when you are not there if you need to unless she starts to trash the rest of the home. Stay on top of it daily.
YOU have a duty, not DD. You offering to clean it with her, etc., is not sufficient. She does not have the duty,
you do.
You could potentially lose the other kids. You need to manage the situation and home, you are putting a kid in the power position to blow up your family or cost you your job. Can you see that? To outsiders it looks extremely dysfunctional, that is why they are coming back. You are oddly passive. Trying to get CPS to "agree" that your KID is in charge and bad is not going to help re: the other kids' welfare, can you see that?
Take her to a psychiatrist and bring photos of the room, find one that works with hoarders if you can.
Is there a family member who is not a hoarder who could take her?