There's really not much for a captive gecko to do, other than eat and maybe find a mate. They're typically more active in the wild, it takes longer to find food, burrows and hiding places need to be guarded. Mates might be few and far between, so going out to look for them could take hours. Even finding a sun-warmed rock to warm up on could take a while. In captivity it's all right there - no need to forage far and wide, no re-digging the burrow other than maybe fluff up the dirt floor a bit.
Wild animals don't roam around aimlessly. They move when neeeded, rest and/or hide otherwise, leaves energy for when it is needed. The less you're out and about exposing yourself to predators the better. Cold blooded animals are also a bit less active.
I'd say yours is out and about at night when you can't see it, does what she has to do to survive, then goes back to rest up, ready for action when needed. Since the only concern is her activity level, there doesn't seem to be anything to worry about.
