I she a Speckled Sussex? I love those guys so much spunk!
I personally think if you are willing to put in the time and love she could heal and pull through. I am sure that you have already done something but I have had an issue with a hawk attack and these are some of the steps I took.
I used a large syringe (without the needle) and did a Peroxide and water flush, then rinse and do a Betadine & water flush, then rinse. Antibiotic ointment is a must. Penicillan will also help. You can get it in injectable form and as long as you aren't squeemish to injecting it will be the best way to get it into her.