First of all, I would try to find another vet who will help you. If you do try to help her and she doesn't recover well, she can still be put down later....but I would give her a chance. It would be best for her if you could find a vet who would give her some calcium injections and later on a shot of calcitonin when the blood calcium levels are high enough...but in the meantime....I would move her to a long low cage so that she can sit on the floor of it and still get the benefit of the UVB.
I would give her some liquid calcium gluconate or calcium sandoz and dust her food with phos.-free calcium with D3 a little more often for a little while to make sure she has enough D3 in her system to use the calcium but without overdoing it.
If she will eat on her own that would be the best option, but not you'll need to hand feed her. Same for hydrating her....if she will do it on her own that will be best.
Good luck with it all...and keep us posted!