Free Spirit
The Chiarian
Swollen and warm makes me think it's a sprain or fracture. I'm not an expert and only going off what you have reported. But make sure to keep her isolated and that she has a bath water that is large enough for her to sit in at least 4" or more deep. That way she can get her weight off it. Depending on the severity it could take a few days to a few weeks to heal.
