A good warm soak in soapy water or Epsom salts could help to get all of the maggots out. Do it daily until all maggots are out. Apply some plain neosporin ointment to it. Screw worm spray or permethrin can help. SWAT, an ointment from the feed store contains permethrin as well and can help to smother and kill maggot larvae. She may have had an abscess on her preen gland before. Keep her away from flies until she is better. Feed her some chopped egg, tuna, or liver along with her feed for some extra protein.