When breeders vaccinate for Mareks disease, it may not be as good a vaccine as the hatcheries use. Plus, a chick must be strictly quarantined away from any possible exposure to Mareksfor a t least 2 weeks from any exposure to dander and dust from the chick feathers. That as you know can go...
Can she move at all, either foot or wing or toes? Are they flaccid, or is she just not able to get up? Is she lying down or sitting, and is her neck normal? Pictures of her and the wound could be helpful. Where exactly is the wound?