Rowena, Unfortunately, I’m almost positive she has rot on her plastron. This is the most common place for water to accumulate under the loose shed. The loose shed will have to be removed as well as any “cottage cheese” looking rot material underneath. I would recommend that the infected areas be cleaned out with Nolvasan and a topical treatment of Silvadene be added also. These can both be obtained at vet offices. When this happens to mine, I usually allow my dbts to assume regular activities in the pond during the daytime since they love to bask anyway and leave them out of the water to dry overnight. Perhaps you could direct a basking lamp into the shelter in the future. You can obtain night-time basking lamps that will not blind her or you could even purchase a ceramic heat emitter instead. On the contrary, most dbts love to bask if convinced that their surroundings are secure. Also, she will bask more if she has shell rot. I used to use them but have since discontinued them. They never lasted very long and I was never totally convinced of their effectiveness. Almost any aquatic plant would be safe. Some common examples are anacharus (elodea) and water hyacinths. This shouldn’t be a problem. I’ve always just used water and a tooth brush. Vinegar is also my choice. Yes, it’s normal for her shell to peel – this often happens towards the end of the summer/early fall. She may lay some eggs in the early summer or maybe even earlier if kept indoors this winter. Hope that helps. There are plenty of others out there with more experience than me so chime in if necessary. – Chun