Hi, I am sorry to hear your daughter is having difficulties. You didn't say how old she is.
I am glad that her father sees that she needs professional help. If she doesn't want to work with this therapist, could they try someone different? If she is young, then it may have been appropriate for the therapist to speak with her father.
Perhaps they could do some group sessions with her and her father/you/step-mother?
What your child wants may not be the best thing for her. Children are often not the best judge :)
What’s the reason she’s living predominantly with them and not you?
Definitely change her therapist. Once trust is broken, sessions will be almost ineffective, as I wouldn’t want to open up to the therapist either if I were in your daughter’s shoes. She no doubt no longer feels safe to disclose anything that’s troubling her.
Re: She ‘chopped off her hair...’ Was this a rebellious fashion statement, a thing she wanted to do for a while, or a trauma reaction to an event that had happened to her? There could be a lot more behind why she did this. Maybe it’s a cry for/attention or help? Did she chop it off, or did someone do it to her?
Where did she go when she was missing for 8 hours? Do you know? Where can she go to be safe when she doesn’t want to come home or go to her father’s? Does she have a good friend? A close relative she can trust?
Is her father beating her? How old is she? Is there abuse going on when she’s there? Is your ex’s new partner turning her father against her and that’s why she doesn’t want your daughter living with them? Do you have a court order about who your daughter lives with? If she wants to live with you, if you want her to live with you and your ex’s girlfriend doesn’t want here to be there-then the only person’s interest being served by her continuing to live at your ex’s is his????? If there’s no court order in place, why can’t she switch over to live with you instead?......,,,,,