I have read your post over and over again. I had decided to not respond. But I feel like I have to. I know these are things we don't want to think about and I'm sorry to even go here but I was abused as a child and reading your post has set off many alarms for me. Please talk to your daughter. Don't give names. Just ask questions. Has anyone ever told you not to tell me something...even family (remind her you won't be mad at her no matter what). Has anyone touched her where she souldn't be touched etc.... If you don't feel comfortable...get a small nanny cam.
I'm so sorry to even throw this at you but you would want to know now and put a stop to it. I truly hope I'm wrong but all of this sounds too familiar to me.