Coconut oil is tremendously healing and I bet it will help
The best part is, if she licks it off, it won't hurt her at all and will even help. You can put a little bit in her food as well. Start slowly though to avoid tummy upset! I gave Izzy too much one day accidentally and she got loose stools. Mine get 1/2 a tsp twice a day, mixed in their soft food. You can also microwave it for a few seconds and coat their kibbles with it
I hope your little one's skin gets better soon, poor thing! I know you've been trying so hard to help her heal up. Have you checked out a vet dermatologist yet?