I had a white rock attacked by a hawk about a month ago. She had wounds which I could see the muscle through, a little less than two inches wide, and she healed up within a week using a topical antibiotic and daily cleaning. She's still missing some feathers on her back, but she is okay.
The best thing you an do for shock is provide food and water and leave them alone and quiet until they come out of it. Get the wounds as clean as you can and then handle them as little as possible. Some chickens deal with it better than others.
If the vet is an option, it's definitely a good idea!
I hope she pulls through!