Poor little thing!
She likely got it hung in wire or possibly a feeder.
I see the upper layer is loose, that may peel fall off on it's own in a few days. The layer underneath is the quick and will generally harden, but I'm sure it's very tender right now.
Personally, I would leave it alone. See that she's drinking and offer her some wet feed to eat for a few days since it will be harder for her to "peck" at feed.
As long as the others aren't bothering her, I would put her back with the flock.
That’s basically what I did. I put her in the run with her two buddies. I have 5 one year old hens and this lady plus two littles (think they might be bantams) we’re hatched in April. So the hens are in the coop, the three younger are in the run. She’s got wet food and a bucket of water. I’ve seen her eat several times.