I've done AIT with all 3 of my kids - and it's helped all 3 of them. I think it's very likely it'll help your DD.
If you go the sound learning centre their initial assessment costs £400 and they do an audiogram. Which will tell you if she would benefit from AIT or not.
Once you see the audiogram, you'll probably see she has heaps of hypersensitive hearing which is causing her pain, and probably explains some of her behaviour problems.
Anyway, the sound learning centre will only recommend AIT if the audiograms show she is likely to benefit.
(I do want to say that although I've had very impressive results with AIT for all 3 of my kids, not all MNers have)
I think you can do the stairs exercise on a spiral staircase. The point if it is that currently she probably doesn't know where her hands and feet are, and is using her vision to tell her that. With her eyes closed her brain has to work out how to balance and where her hands and feet are. And it is doing that 3 times a day which improves the cerebellum.
Which is the starting place to improving all her problems.
Why don't you do the stairs exercise yourself on your staircase to see what it's like.
I hate doing it - it makes my brain hurt
. But my DH who has no coordination issues finds it easy to do.