Just a few thoughts.
I would stay away from all poultry, poultry flavorings, and poultry fat, at least until she is strong enough to challenge with things like turkey or duck.
You can probably rotate in some lean beef, lamb is probably cost prohibitive. I used to give my girl eggs in the morning and pork in the evening. Max here is okay only on beef and lamb, so he gets only beef, occassionally lamb, and salmon about once a week.
The body needs nutrients to repair. I would try to find a multivitamin to help repair. You will need to add some calcium. I've been using a product called Nutramin for that, but for years I used NOW calcium carbonate. I would consider adding some beta carotene, and also zinc. You have to be careful with longterm zinc, but short term, the body needs it to heal. I would also consider a b complex supplement. I like country life's action B-50 because it is yeast-free. That is what I used for my 35 lb girl. For Max here, I use Jarrow's B-right B complex, which is probably a better product and also yeast free. Honestly, I don't know which one is really better. Vitamin C is also important, as collagen is an important part of the skin.
This would be great if she is already getting better. If this is mange (and it sure looks like it could be), then the key in the long run will be to rehab the immune system.