I trust you checked the temperatures in her enclosure? You mentioned something below about the lights being off for 4 hours? (assuming this was a typo and you meant the lights were on for 4 hours). As other suggest I would take her to a vet just to make sure she doesn't have parasites or some disease.
What did she eat last? Any chance she may have eaten something that you didn't want her too (ie some insect flew into her enclosure or forgot to wash her greens?) Though she is getting older I don't think she would be suffering from old age but then again I am no expert. Did her change happen suddenly, as in fine one day, lathargic and shrivelled up the next?