Yes, bright sunlight (or any sunlight) bothers my eyes. I drive with the visors down in my car all the time. It's a common symptom of MG.

Is your neuro testing for MG antibodies? If she is repeating tests that have previously shown a positive result, there is really nothing to wonder about, as once you are positive you have MG, plain and simple (barring a lab error.) If she's trying to gauge the severity of the MG by the antibody level, then that will not get her far as the levels have little to nothing to do with disease severity, especially if you are on meds.

If you are having weakness or fatigue easily in any other body part--difficulty swallowing, smiling or speaking, lifting arms or using legs--then MG has likely generalized. There is no lab test that will tell you that.

I hope the meds start working fast and you can feel better again. MG flare ups are the pits!