But this is as much about providing consistency and structure, than simply expecting a child to consistently follow your structured rules. And she needs consistent love and a structured home first imo and a consistent response to her, based on understanding and patience. She hasn't got any stability and the person she is living with atm is only temporary. She has abuse trauma trust issues and, from what I can make out, doesn't healthily or openly express what her issues are attached to. I don't think unchallengeable rules and punishment should be the priority here. Unconditional love, understanding and trying to support, help and accommodate her, while establishing structured decisions on boundaries (for both the caregiver and child) and accounting for behaviours associated with that trauma, is a better approach imo

I agree to a point. But I also feel that enforcing your will on a child that has already had all control and previous structure taken from her and is now trying to establish how she feels and rely on herself for structure and security, needs to be made allowances for. Plus, other than going outside without telling OP, Which I believe was more about pushing for an emotional response of care and concern for her, than it was boundary kicking and therefore, love, care and worry should have been the first reaction and not a stern one about rule braking. She hasn't done much wrong imo. What we have been told she does wrong:

She wants to be allowed to be independent and rejects practical help ~ so what? Her therapist says this is because she hasn't been able to rely on her carers in the past so has decided it's better to take that responsibility herself. If she feels this gives her her own structure and stability, then providing she it isn't dangerous, why not allow it?

She wont eat and lies about that when quized ~ any expert will tell you that punishing a child with an emotional triggered ED will only make that worse.

She wont go to bed ~ Obviously A line has to be drawn here but experimenting with adjusting where that is drawn is perfectly acceptable imo. She has suffered severe trauma so time alone, with no lights or stimulation providing a distraction from those thoughts, could potentially be very distressing. So why not bend those rules to accommodate this possibility?

You are right that a child will push at boundaries and with none in place could become unruly. But it is also individual to circumstance and about finding a healthy a balanced structure based on those. Imo this child deserves that and needs it too help to rebuild her trust of adults and caregivers and to feel she is of some importance to these people, and not just something belonging to them that they can do what they want to and get rid of when they please x