Just an extension on what Spirithorse said, if she wants to move, its best not to do this by making her go forward because this could get out of hand. I.e. She could take off and/or buck. I'm not sure if Spirithorse meant to say this or not, but its probably a good idea not to do too much forwards, but mainly channel the energy into backwards and sideways. Or if you do go forwards, use fairly small circles. Then after a little while, try her again and see if she'll stand still. If not, get her moving again. She'll eventually stand still.
Other methods that I have used.
- everytime horse moves, put them right back where they started so they learn moving does no good as they always end up in the same place.
- reward for standing still, I.e. Relax rein contact and allow horse to just stand and rest.
- keep calm yourself! If you get upset yourself, its going to make your horse worse
The above can and should be done on the ground also
I hope this helps you out a bit