digging behavior

Hi, first time poster with a question.

Sadie my female is 2 years and a couple of months old (got her as a hatchling from HISS at the 2005 Austin Reptile Show) now. She's become more active lately since I moved her enclosure into a different room in the house, and also seems to spend far more time outside of her cave (one of those exoterra reptile dens) during the day, raising her head almost like she's sniffing the air. She's been shedding recently and also has not had much appetite, which I've been attributing to the shed. Yesterday afternoon when we came home I noticed a behavior I had not seen before. She was in the front corner of her enclosure busily digging up sand. I have calci-sand as substrate maybe a half an inch deep or so. She dug down to the glass bottom.

Anyone got insight into what's going on with her? My immediate thought is that she's "nesting" but as she's never been bred and I see no signs that she has eggs I don't know. Can she produce eggs without mating? I'd assume they would be infertile, so does she reabsorb them or actually lay them? If that is what's going on, what do I do if she does lay eggs?

I've never gotten her tankmate for fear of it being a male and creating leo babies that I wouldn't know what to do with. But I never considered that she might still lay eggs without a mate.