Look at that smile! It’s a bit hard to tell for sure (you’d probably need a boarded veterinary ophthalmologist familiar with reptiles), but if it is ‘crossed eyes,’ the technical term is ‘strabismus.’
In mammals, that sort of thing is generally from birth (‘congenital’) and often genetic (‘heritable/hereditary’). Sometimes it is correlated with neurologic signs, but very often not, and generally not harmful. So that would be my guess. Most likely not a problem, unless you’ve noticed any difficulties or strange behavior? She might benefit from an extra-simple, consistent cage layout, if you’ve noticed that she has difficulty navigating.
I’ll go drag my ophthalmology text out of my car and I’ll edit this if I find any new info of use.
edit- everything I read seemed to support the idea that any ‘medial strabismus’ -crossed eyes- is most likely something she was born with, if both eyes are doing the same thing and there are no other symptoms. Watch her to see if she has any problems with balance or holds her head funny.