Oh, one more thing, she doesn't need those mineral supplements every day. Take another look at the caresheet to see what it says about supplements, what types and how often.
Soaking doesn't hurt a tortoise, there is no harm in doing it longer or more often. I just haven't found that she wants or needs it. She's from an arid climate and doesn't need it as much as some other types of tortoise.
You'll quickly find that we recommend daily soaks for just about all new tortoises or possible ailments! It also stimulates their appetites and while I don't think your tortoise is starving, she looks less plump to me than she might, as least for spring time, when they are voracious eaters. Is she eating well for you? The diet you have her on is okay for now, but she'd be bettter off with spring mix, which usually contains bitter greens, like frisee, radicchio, and endive. The Ready Pac Santa Barbara mix is available at my Albertson's and some Smart and Finals, That variety is a really good mix: easy to find and serve. But really, typically anything labeled spring mix or perhaps Italian or spicy mix is a good bet.
you live a million miles away actually ha-ha you seem to love him so, you should keep him, also, in case you have other pets roaming around the house please be aware that torts and turtles love eating pet hair, like cats or dogs', unfortunately it blocks their digestive tract, killing them, just in case you have anyhello, i live in Los Angeles area, if you are looking to have him adopted, i rescue torts and would add the guy to my group of happies, let me know