Obviously the most important thing is to get her back to a stable condition . . . and I hope she is there right now.
You can worry about the leg later. Yes, accupuncture is an option but if the nerves are severely traumatized then there is little chance that it will work. You should definitely consult with a neurologist before you make any decisions about an amputation.
I had one patient with severe nerve damage after being hit by a car. She never did regain the use of her leg but the owners did not want to pursue an amputation. They said that it helped her balance and she used it to hold her treats. Occasionally she would chew on her foot so it was constantly bandaged. The dog certainly seemed happy enough.