First off if you get her skin moist you gently rub head to end and remove the skin. Only if it rubs off, do not pull it off. You really have to move the snake from its enclosure to feed I don't see why she won't end in a different tank, for some ideas try a google serch from feeding problems and you should get some people who have ideas to try and get her to eat in another tank. As far as getting her to eat prekilled, Which I just got my 10 month old bp to eat prekilled, kill the mouse when you get her in another tank and take tongs and run the mouse aroung like it is alive. Get close to her with it. Let her smell it and just don't put it in front of her. Snakes are hunters and like to at least have some chase. About the substate don't wait till it is to late call a vet and just ask. Good luck!