The enclosure sounds a bit big but if 3 sides are covered it might be okay. Aspen would be a better bedding, could you lower the humidity some? How deep is the substrate? It might also help to raise the warm side to 90-93 and cool side to about 80. How often are you checking on her? Does she show these symptoms when she doesn’t know you’re there? It could be that you’re stressing her out from checking on her.