Wow! What a blessed little hen, and you must be an awesome chicken momma to be willing to do all this for her! Your kiddo's are going to learn lessons in love, patience and caring thru this!
I haven't read all the posts, but I saw where someone recommended a silver ointment and I can certainly attest to how wonderfully well those work. Docs used to put silver into the eyes of newborn babies cuz it prevents infection so well. I had a sweet banty hen attacked last summer, lost all the feathers on her belly, rump and one leg, as well as some deep open wounds, one the size of a quarter. I have liquid silver which I put into a small sprayer so that I could mist it onto her with rubbing the skin/wound at all. Also, it didn't hold in moisture that way. Aloe vera gel or juice is very healing and I put that on everywhere after the first day to soothe and start growing new tissues.
Also, raw (uncooked) honey is awesome on wounds. Totally antibiotic, safe. Also used by docs until after WWII. Perhaps you could thin it with distilled water a bit so it wouldn't pull to apply it.
At the health food stores you can get Bach's Rescue Remedy for shock, stress, fright and nerves! Wonderful liquid, works within minutes ~ I've used it on my kiddo's, my 80 yr old momma, dogs, cats, horses and my lil' hen last yr. There is a spray which works well for animals, just hold it a few inches from her face, or spray anywhere on her exposed skin where there's not another med. Its perfect to use immediately after an injury, but will help support her as she heals and starts to want to move about or wonders where she is!
Hope you'll keep us informed as she heals! Can't wait to see the pics of Holly all happy and healthy! Blessings to you all!