there. Thanks question. Im sorry to hear about your dogs troubles but glad she has such a caring owner as you. Let me see if I can help
Burned skin is in fact very delicate, you are right. Protecting it is very important. There are some things you can try.
SSD cream- silver sulfadiazene creme is excellent / recovering skin. It coats well and protects it
You could also look into some dog leg wraps made from neoprene or some other support material. These might provide more protection when she is outside in the snow. Here is an example: http://www.backontrackproducts.com/Therapeutic-Dog-Hock-Wraps-p288.html
You'll have to search around to find ones that cover the right area
I hope this helps. Good luck to you. Let me know if you have further questions.