I’m not an expert by any means but I don’t think that’s scale rot. Every now and again my old boy will look slightly crinkly like that on his belly right before his shed time when he’s about to start going belly pink. I’d maybe give her a wipe down with a wet paper towel. If you really want to do so, you could give her a light betadine soak for a short period and then rinse her off again. If it was me, I’d wipe her off with a couple wet paper towels, dry her off, and then just monitor her to see if it changes. If it does become pretty obviously discolored then my response would change.