My barred rock has survived TWO fox attacks (and one red-tail hawk attack). Both left pretty nasty but shallow skin injuries where feathers and skin were pulled off. Both times I brought her straight inside the house and hold her in my lap in a towel while checking her over and kept her inside for the rest of the day both times as she was too scared to go right back outside. Then I carried her into her run where she knows she is safe and kept her and the rest of the hens in. She was able to roost on her own.
To treat her skin wounds I snipped off any hanging skin that I could tell would just die anyway, and removed the pulled-out, stuck-on feathers, and gently dabbed with a clean, wet, warm washcloth, and applied antibiotic ointment. Even over messy/bloody areas. For the next week i went into the coop every night while she roosted and applied the ointment. She did heal although there are some bald spots and she never developed an infection.
The attacks changed her behavior for quite some time. She was very skittish and scared to come out of her run, and she also dropped in the pecking order immediately. She eventually returned to normal both times, although she never came back to top pecking order! She remained skittish outside for many weeks, though.
She will probably eat/drink again as she calms down. You can offer her treats to tempt her, all kinds of soft and healthy foods and fruits. She might also prefer to be back with her flock? She may go back to normal more quickly that way. Good luck!