These two seem to contradict each other:
- can be strong willed about trying to get her to understand something (why something is not a certain way, or ok)
- does not argue or talk back to foster mom (fm will not allow it)
So I'd want to know how she expresses her "strong willed" personality if she doesn't talk back. Does she agree with it and then not do it? That can be a whole other issue to deal with. Or is it something else?
And I'd want to know *how* the foster mom doesn't allow her to talk back. Whatever her technique, you'll need to learn it as there is no guarantee any other ways will work. Is that OK with you?
Also, bipolar individuals often stop taking their medications when they feel good. Even if they knew they needed them before, they feel fine later so they stop. So I'd want to know how long she's been diagnosed with bipolar, and if she's been medicated long enough for her to have conceivably felt good and thought about not taking the meds anymore, and took them anyway.
I'd also want to know how long she's lived with this foster family. Have they had her long enough to have gone through a long honeymoon period, and be out the other end to more normal behaviors? What was she like when she was first placed, and what was she like soon after the honeymoon ended? Kids often regress to those same behaviors after major upheaval, and moving homes and families qualifies as that.
With a child this afraid of rejection, I think I'd have LOTS of conversations with this child's foster family (and previous ones, if she has any), doctors, therapists, teachers, etc before being introduced to her. Anything you can learn from somebody other than her probably should be learned that way.
That's my take on it anyway.