To answer your question...first, I need to ask you a few...
How high exactly are her numbers? And what type of Diabetes does she have?
If she had Type 1 diabetes and her levels exceed 250, I'd suggest testing for ketones. Ketones can make you feel just plain icky

...yes, that means stomach pains, nausea, etc. If her numbers are extremely high, please don't wait...contact her doctor immediately.
If she has Type 2, and her levels are high...I think it's also possible that her numbers are affecting the way she feels. However, I don't think it's as serious of a situation, b/c Type 2's generally do not go into ketoacidosis.
However, you have to trust your instincts... If you feel like something serious is going on, I'd get her checked out.
Hope she feels better soon
