Boy.....That does sound like mareks doesnt it. If you can keep her eating, that is a good sign. Dont forget just a tiny bit of grit if you wind up feeding like this for a while.
....We lost a flock of dominiques many years ago..They were my pride and joy and they indeed had mareks,all of them, same symptoms, all had to be destroyed. Our vet did it for us .
.One hen survived, thou paralized for quite a long time she never lost interest in eating or drinking, she was the only one whos vision -and head and neck still worked. We had to feed her several times a day by holding her up and putting the food directly in front of her, with a little grits, and kept the back of her very clean.Moved her legs littel at a time, it took long time but she got to where one leg started working then the other but never walked 100 % but got around pretty good.and beleive me she was frozen in posture for a while.legs straight out behind her.
I posted an article in here a while ago, If your chickens breath, they have been exposed to Mareks. It is just everywhere .wild birds can carry it, it just travels on the wind, very contagious.carried in dander, feathers everywhere. We now vaccinate every new hatch for it, A hassel with the tiiming of it and the vaccines but in the end stops a lot of heartach. If I lived closer, I would do it for you .But you can learn to do ityourself. It is not that difficult. newcastles and coccsidosis (sp). You cannot feed antibiotics when you give the cocc vaccine as it will cancel it out at least for a short time. just follow instructions on that.
If you buy any new chickens ask the breeder what thier vaccination policies are. I think as breeders especially those of us who hatch out thier own really need to be on the ball with this. They may offer classes in your area, in the future, its the best money you will ever spend.