Windgalls or a splint?

A splint is in the cannon bone so that is not what it is. Is it possible she may have just stepped on herself? If she is not lame and the galls don't affect her any, she will probably be just fine. Have you tried soaking her leg in saltwater... make some strong saltwater, soak a small towel or something in it, wrap the leg, soak it a bit. Then leave the rag on and hit the leg with a medium strong flow of water from a hose. The hydrotherapy of the water and the absorbtion of salt, can actually take the windgall/windpuff swelling down :-)