Okay, don't panic. Is she maybe getting ready to shed? Maybe too early and you can't tell? Did you see my thread about Razzle that just got updated? He did that to me too! It's so scary when they have been eating small meals to begin with! I bet that's it, though. Had she been hiding, maybe even just the previous day?
I would do this: Give her her mouse (pieces), leave her for an hour. If she hasn't eaten, reheat, leave her an hour. (Yes, I know it's icky to reheat pieces)! Since she's normally a _good_ feeder, I'd just quit and try again in five days. (If she was a non-feeder, I'd reheat again and leave her overnight with it. Since she's a reliable feeder, she just doesn't want to eat right now).
And since she has a history of regurge, if you even suspect she is blue, I'd just quit. I would never feed her when she is blue. Maybe as an adult. If she will even eat. Plenty of mine will skip one or two meals when they are blue. Just offer again in five days, or if you confirm that she is blue, after she sheds. The same evening is okay.