Pictures are helpful. You are dealing with flystrike, which can be very serious. You did the right things so far. You will need to check her several times a day to make sure that you remove any maggots that continue to hatch, use tweezers if necessary. Move her to a place where no more flies can get to her until she heals. Continue to use the veterycin, or you can use plain neosporin ointment or plain triple antibiotic ointment on the wound. Trim back any feathers that are getting in the wound, this will help keep it clean, and help you see to make sure you don't miss any maggots. Recovery depends on how soon you caught the flystrike, how severe the wound is, and infection. If maggots did not enter her abdominal cavity, she has a chance. Make sure she stays hydrated, that is more important than food initially. Some electrolites in her water, sav-a-chick, pedialite, gatorade is helpful, dip her beak to see if you can get her to drink. If you have some poultry nutri-drench give her some of that. You can try scrambled or chopped up cooked egg, some canned tuna, or mixing her feed with water to make a mash to see if you can get her to eat. Hopefully she will start feeling better and perk up and start eating and drinking on her own. Here is some more info on flystrike:
https://www.theartofdoingstuff.com/flystrike-a-chicken-killer-cuddles-beats-the-odds-again/
https://the-chicken-chick.com/flystrike-in-backyard-chickens-causes/