You would be amazed at what they can come back from. Put her in a quiet place, inside (so no flies can breed in her wounds). See how she is in 24 hours, then make a decision. I had a chicken pretty much skinned alive last week by a strange dog. She was alert, so I sprayed antibiotic on her wounds and took a wait and see approach. She is doing fine now. She looks just horrible from her severe injuries, but will heal, given the chance. I did give her amoxicillin in scrambled eggs for a few days, too. She is now queen of the house. It will be months before I dare put her back with the flock. The thought of a rooster trying to mount her gives me nightmares!