Firstly, I'd suggest cleaning all the areas of broken skin with mild salty water. If you can lay your hands on some iodine (Betadine, for example) then clean the areas with that after irrigating the wounds.
If the wounds do not smell, they may not be infected, but you should isolate the hen from the rest of the flock and at the very least, give her some vitamin supplements / electrolytes to help boost her immune system (thus helping fight off any secondary infections).
I'm sure the injury experts will be along soon enough to give further advice, but I hope that these "first aid" suggestions help in the meantime.
All the best
CT