Floopy, I think part of what Starlight might have been getting at is - it doesn't really matter what the label is - if your child needs help, then she needs help (and I note you say she is getting good support - which is a great start)
I have a probable PDA dd2, and I really don't think that there is much difference at all between HFA/AS/PDA - the levels of anxiety might fluctuate, there might be language differences, but overall, in terms of how to help, and what to do - it should always be centred on what the individual child needs.
I worry a LOT when I see that there are blanket statements being applied to the differences between PDA and ASD.
form reading brandy77's post - I would look at that rundown (delayed speech, but then reasonably fluent, albeit with eccentricities) and say HFA.
I have read lists of supposed difference between ASD and PDA, but disagreed with almost all of wht was listed as an ASD "trait", to be contrasted with how PDA presents, and so for me, the list of differences is flawed (and I was keeping my dd1, who has severe ASD in mind when reading them - contrasting my own 2 children, if you will)
in my household, the difference between dd1 and dd2 is langugae, pure and simple. dd1 has a huge language delay/disorder. dd2 has idiosyncrtic language, and a few comprehension problems - eg she doesn't understand idioms or sarcasm. but her language is otherwise very advanced, and she sounds like a mini-professor, with very precise diction.
other than that, the traits that the 2 show are incredibly similar. dd2's anxiety presents itself differently as she can refuse and manipulate in language terms. dd1's anxiety is absolute, and comes out more as a sheer panic at being overwhelmed. however, once you start unravellign what is actually going on, then we deal with the anxieties in exactly the same way (which is also why I am mystified by the often repeated refrain that PDA is dealt with in an entirely different way)