have you checked the bottom of her foot? check for any sore or scab, or possible splinter etc.. or any heat or swelling. check the toe nails and between the toes.. she may have Bumblefoot.. or just a sprain.. confine her in a smallish area with food and water and soft bedding so she can rest the leg. give her some plain yogurt and extra protein..such as cooked egg .. if she has a sore on her foot..(Bumblefoot)..she'll need treatment. post back if you find anything. lots of threads here about Bumblefoot.