Red-eared slider showing gravid signs again shortly after egg-binding treatment

Hello, I have a 20-year-old female Red-eared slider and would appreciate some advice. She has been laying infertile eggs once or twice a year for the past ~5 years (since she got her new tank), in the water, because the nesting spots I provide are not to her liking. Recently, she was egg-bound for about a month and required treatment with Oxytocin, after which she laid 14 eggs on March 7. She is now showing gravid behavior again (since March 29), which seems very soon after the previous clutch. I have tried providing a nesting box, but she refuses to use it. When placed inside, she becomes stressed, tries to escape, and does not dig. I have tried different substrates (peat, then wet gravel similar to her basking area) and different approaches (short 2 hour  sessions, overnight periods, moving her while digging), but nothing has worked. She prefers to dig on her basking area, but the substrate there is too shallow for nesting. The only thing I could think of right now was to pile more gravel onto her basking spot than usual (this happened today, she has yet to use it). When gravid, she tends to eat very little. Currently she has reduced appetite but has not yet lost weight. My questions: -Is it normal for her to develop another clutch so soon after laying? -Is there anything I can do to help her lay eggs naturally and avoid another case of egg binding? -Should I be considering a vet visit sooner rather than waiting? -Are there any changes I should make to her nesting setup? I would really like to prevent another stressful intervention if possible. Thank you very much for your help.

I'm afraid to say that this isn't a species I have much experience with; however, to answer your first question, the published literature does suggest that it is quite common for Sliders to clutch 2-4 times per season; the shortest interval between clutches I can find on record is about 10 days, and the longest is 46, so she would seem to be sitting comfortably within those  brackets. However... She has clearly clutched successfully before, and is not doing so now. At her last clutch, she was egg-bound and required medical treatment. And now she is displaying gravid behaviour without laying again. So to be honest, I really do think that seeking veterinary advice (from a veterinarian who is familiar with the species, or at least with chelonia in general!). My concern would be that you're seeing the early stages of another egg-bind, and a second in quick succession could be quite difficult for her to manage. I'm hoping I'm wrong, and that by the time you read this she will have laid a nice new clutch, but if not, I really do think further examination is indicated. Good luck with her!

Nice detailed discussion there—really helpful for turtle owners dealing with reproductive stress and possible egg-binding. It’s always worrying when a red-eared slider shows repeated gravid signs so soon after treatment.