I am so sorry about your girl.
If it were my chicken, this is what I would do:
Trim away all feathers that come into contact with wound, and around edges of wound so it has a birth of a half inch to an inch around it. Use a chlorhex solution to clean out the wound. When I worked in vet med, we would mix up chlorhex into a sodium chloride bag, hang the bag and open the line so the jet of water sprays off the wound. If there are any pockets, they need to be sprayed out as well. They may need to be opened up and a drain inserted (a drain is a flexible rubber hose but you would need the help of a professional to do this and also something to numb up the area). Your biggest problem will be not getting air to those pockets. If you can open those up, spray them out very thoroughly, and try to keep them aired out well. Animals will get septic infections with puncture wounds, so a broad spectrum antibiotic will be important right now as well. If you want to stick to more natural therapies, I would give her as much raw garlic as she will eat, as this is a natural antibiotic and antifungal.
Good luck.