Oh, poor thing. Is her shank broken? It looks bent in the pic.
A little more info would be helpful. How did it happen? Can she put weight on it?
I see the red/bloody? area between her toes. Is there any damage to the bottom of the foot? Bite? Puncture wound?
How is she acting? Active? Shocky? Did you check her over for other wounds?
General first aid is to keep her quiet and warm (not hot), so she doesn't do more injury. A cage or dog kennel is a good option.
Just saw your post...
That's what I would have done. The antibiotic ointment will help. If she has puncture wounds, she will probably need some antibiotic. Tylan is one that people often use, but I cannot advise more on this... have never used it.
Their recovery abilities are amazing, so infection is probably your biggest concern. Set her up in a quiet place away from the others with food and water so she will keep still and can heal. It will prevent others from picking on her and make it easier for you to monitor and treat her.