Colloidal silver is great for wounds btw. If the wound is deep, keep it wet. You dont want the insides to dry out. If the wound only goes skin deep, you can let it dry if you wish, but you can also keep it creamed up if you believe it may get infected. I use colloidal silver for just about everything viral or bacterial and you can get it in a cream which will keep it nice and clean.
If you do let it dry, I would recommend still cleaning it with a antibacterial spray about 3 times a day until it actually gets healed enough. The dryer it gets, the more pain it may cause as well so if she gets more lame, its probably from soreness.
Because of hawks and fox, I keep my chicken penned up unless I have my guard dog out with them. I'll leave the roosters out full time with plenty of roost though. I got Liege fighters for this reason alone. If you're brave and in a state that allows, you can buy game fowl like a Warhorse or the like and although you usually cant keep them with your normal chicken, they make great guards and will not hesitate to at least try and kill a fox, giving everyone else time to escape.
Other than that, an electric fence is your best friend from ground attackers.
There is a very expensive ointment called Terrasil. I used this on some major wounds back when I was a k9 handler in the military. It lives up to the hype of very accelerated healing. It's extremely expensive though but figured I'd throw that out there. I've used it on wounds that have gone to the bone and it has healed them extremely fast.