What kind of bulbs are you using? The Coil type causes eye problems and the halogens are too harsh. Any of those might make her not want to be out with them?
Also some older torts take a while to get adjusted to their new home. Lots of them the first day or so will act normal checking everything out, then they do what yours is doing. She may just need more time to adjust to her new surroundings. Best thing for that is to make sure all temps, etc is correct then carry on with giving daily fresh food and water and don't mess with her too much. Try to set a routine with same time feedings, lights out, on, etc and when you take her outside. This helps with them getting used to what's going to happen at those times.
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All my lights are on timers, on at 7- off at 4p. I used to feed her every morning as soon as she started moving around. In SoCal, I believe eventually, I'll be able to keep her outside year round once i get the outdoor setup complete. For now the current box and occasional afternoons in the secure back yard will have to do unless that is harming her.