Hm... I'm no expert, I can only go by the experiences of one corn and one royal, and my exotics study at college. Plus being good mates with complete herp-maniacs.
Lol
What species is she? She's not a royal is she? Such pains to feed.
Have you tried blooding or braining the mouse? Apparently it usually works. Other than that, if she continues to refuse feed and everything is fine otherwise, can you force feed? I know with our baby royal he was refusing to feed, so we had to force feed with pinkie mice because they're small. Just to encourage them to eat more. If you open their mouths and stick in there, their mouths normally take over and just start taking it instinctively.
Theres been no recent changes has there? Lighting, heating ect... Did she definitely get off all the shed?
Can't really help beyond that... :S