Usually, chickens heal pretty quickly. But do keep her separate til the blood is gone, as blood causes chickens to peck more. They can peck at a small wound until it kills the chicken with the wound.
If the chick heals, you will then have a new problem, reintroducing her to the others. She will be seen as being at the bottom of the pecking order which, guess what, means she will get pecked again.
Ideal situation is if you can identify one or two who are doing the pecking. Then you isolate them for a few days so that they in turn will be at the bottom of the pecking order upon return.
Good luck!
Chickens will peck. When we have to intervene is when they draw blood.