My daughter is 28 now and was diagnosed aged 7. She is also adopted and has a whole history of early trauma. We went through the whole range of assessments and suggested diagnoses, including attachment disorder, but PDA made most sense to me - and this was back in 2006 when PDA was relatively unknown.
My daughter had all the PDA symptoms, not just the demand avoidance but also the role playing, fear of people in character costumes (Disney land Paris was a nightmare) and lots of asd traits. She was incredibly outwardly sociable (though it was all an act) and no one ever believed she was autistic, and this is typical of PDA and another aspect of role playing - in fact she was way too, inappropriately sociable, and she would talk to adults like they were her peers. She had no friends though and relationships with other children were spiralling.
She was in the smaller group of PDA kids who present under the radar at school. She basically did no work but was so seemingly cooperative and no trouble, so teachers left her alone. Then she would explode when she came home.
She was doing zero work at school - i couldn't see how she could ever manage secondary. I therefore started looking into specialist provision and I got her a then Statement in year 6 and a place at a speech and language independent school. She was collected by minibus from the house and dropped off each day. And she tolerated this. Im not sure what would have happened otherwise.
Then for post 16 she went to a tiny alternative provision for nervous students. We tried to visit the local 6th form college but she bolted the minute we got inside.
So she stayed there for 2 years, then the local NEET scheme got her an apprenticeship and she has been working ever since.
She is able to do more and more as she matures and sees the intrinsic benefit - she is currently learning to drive forcexample, but that's only been possible in the last few months.
She definitely is on the autistic spectrum and I find that PDA is the best explanation for her difficulties. But it involves much more than demand avoidance. It's the role playing, fear of people in costumes, superficial sociability....I'm not sure that the OP's daughter has any of this.