Crazy locked up horse

The same folks that make the Jolly Ball also make a product for stalled horses called the Jolly Apple or Stall Apple or some such thing. It's a toy that hangs safely in their stall and gives them something to do. It also has a treat in the middle so they can fidget with trying to lick out the treat. Horses graze constantly so when stalled, it drives them crazy. Keep free choice hay and one of these Jolly Treat Apple things in the stall.

have you considered getting a ball or some other "worry" toy in her stall for her to mess with, much better than getting bored and to start to crib... might want to ask the vet about it