Thanks for all the replies.
I will definitely work with getting her to respond a bit at a time even if she moves to start off with. And I will also try the treat between the front legs to stretch her back.
As for the chiropractor I really doubt that the problem is because she can't or because of pain. She just doesn't know what I am asking her to do. I also can't get a chiropractor or vet out cause my dad owns the horses and he wouldn't think that there is a point because she is fine otherwise so then its not a big deal. But like I said I am 99% sure its not a health problem so much as she is confused.
Thanks again for the advice. I really appreciate being able to ask a question and get lots of responces in such a short time.