If you read through a few of the old threads in post 95, many of the hens had most of the skin off the back of the head or neck, but recovered. None were as bad as your pullet’s injury though. You described some seizure activity and possibly wry neck which could mean that she had a brain injury. The skin, believe it or not will grow again if you keep it clean and moist with ointment, but it will take a couple of months. I would see how she does in the next couple of days, and do what you think is best for her. It would be a tough decision to put her down if she will eat and drink, but if she doesn’t start acting more normal, she may not thrive. A lot depends too on how much time you have to devote to her care while she is separated.