Honestly I would try the ivermectin route. If she is already paralyzed she might not make it but ivermectin is just a good thing to have for the future. She might be to far gone. Give her some vitamins vitamin e I hear works sometimes for paralysis. I've had chickens that would become gimp like...
Have you sprayed any chemicals that the chicken can get into? Also is the feed moldy and or water clean? Also do you have any cats that can get into the area?