had this happen before too and its honestly hard to tell - bulge could be pregnancy or her just getting chunky. was there a male around or has she been kept alone?
The temperature could definitely be part of it — geckos get sluggish when it's cool and their appetite goes with it. Try bumping it up a bit and see if she perks up. Just curious though, is she pooping normally now since the diarrhea thing?
That constant monitoring anxiety is so real. But if she's been healthy and exploring for nine years, I'd think the quiet room probably won't throw her off.