Does she have physical trauma? Maybe you should look her over closely to find out, but I doubt any medication is necessary, even if there are cuts. You could wash out cuts with saline and apply bacitracin.
Get some cracked corn or meal worms and feed her. She should not be afraid to get close to you, but she will want to be near a bush or something for cover.
I had a hawk kill one of my hens a few days ago. It ate her head to the bone, but left the rest practically untouched.