Could be severely bruised, yes, they can break bones in the foot, but I still recommend the Epsom salts soak. Most chickens like it, although they don't tolerate it for more than about ten minutes. It WILL help with pain, inflammation, and swelling, as will the baby aspirin. Be careful with the aspirin though, as I remember one person on here had a problem with it when they gave it twice a day for an extended period of time. Just give it for the first few days, and then if she's still in pain you could drop it to once a day. Yes, keep her confined, it is just too much stress to have to deal with if she's in that much pain and can't walk, and especially if the others are picking on her. Keep her close enough to the flock so that she can see and hear them, and they can see and hear her. Otherwise, she might have problems re-integrating when she is well enough to go out. I always like to give my birds in hospital cage extra goodies, treats, a seed block to peck, grapes or any treats like that to keep them cheerful and give them something to do. .