Here is my experience. June 4, I had a 6 week old chick who flew over the 4 ft divider fence between the chicks and hens. (Shade cloth is now hung top to bottom to keep anyone else from 'crossing the line'). When I found her, she was bloody and her scalp was gone. Horrifying and traumatic for all of us! Based on all I have read here, I cleaned her up at various times with soap & water, bactine, iodine, and hydrogen peroxide. Then I would add the neosporin. I did make her an electrolyte solution (found here) and gave her antibiotic in her water. I had her in towels, but then moved her to a tub with pine shavings, waterer, feeder and mirror (so she wouldn't be lonely) and her environment would not be so alien. One the third day, she started eating chick feed mixed with lactobacillus (whey from yogurt) and molasses. This was a special treat when she had pasty butt. I have also added Rescue Remedy, putting a drop on her beak. I was interested to read elsewhere that the yellow/green on her head might be the healing process - I have been trying to scrub it off, but causing more bleeding (and peeping!). I also started putting Blu-Kote on her head when the yellow/green started drying up. She is now in a dog kennel, inside the chick's run. It has been 2 weeks to the day and she is healing quite well and spends a few minutes mingling with the other 7 chicks each day - supervised since a couple want to pick at some skin on her neck. However, she was the boss before, and I think she has a good chance of regaining her status!
My question now is, how soon to let her mingle freely? (I was actually here looking for a chicken helmet when I saw your post.) Regarding your little chick - you will be surprised how fast they bounce back. The day my chick was attacked, I was here on the forum looking up when/how to cull and injured chick - so glad I didn't have to do that!
Best of luck to you and your little chick - please keep us posted!