I like the above ideas! I do know that me and my boss had a horse come through that was awful (sounded a lot like you mare actually lol) in a stall. In fact, he kicked his stall door down and bent the hinge so we had to cut the stall in half to get him out. After we tried the toys, and several other nice things, my boss pulled me aside and said "Wanna see an old cowboy trick?" I said sure and we sat down. She waited until he kicked the door and very quickly got up and kicked the door back. It gave that horse quite a shock that he stopped kicking at his stall (she did also say that she usually had to do it two or three times on others.) The same horse had a pawing/running out of his stall problem and every time she caught him she chucked a brush at the side of the stall or door. The noise made him stop and he never saw the brush coming, but knew if he did it while one of us was around there'd be hell to pay. :) You might not ever be able to fully get her to stand like you want (and I second what franknbeans said, show horses + stall = disaster and noise), but she might at least stop doing it while your around! Good luck! :)
Just because I forgot: Is she getting out enough? Part of her problem is boredom and maybe if she gets out enough that will be enough to keep her calm in a stall. I have a gelding who paces and destroys stalls when he's in them regardless of what you do to curb it, so he's out 24/7.