First thing to do, is get that wound cleaned up. Rinse it with a saline solution. Then you might want to apply some antibiotic cream. I use neosporin. Keep her in a warm place, to help with any shock she might have. Keep her away from all the others, as they will only continue to pick at her wound.
Then you need to figure why they might be picking....are they crowded? Have they been locked up more than usual due to weather? Maybe she had a wound from a rooster breeding, and they saw it, and just started picking??
Keep us updated....oh, and welcome to the BYC. Great group here!