I would be hesitant to go the medication route before trying to get a better idea why she is so anxious. There may well be things behind it that need to be addressed, not masked by meds.
Once that has been done the second step would be for her to learn some simple relaxation or self-hypnosis techniques that would let her take
controlControl
Control rx of her stomach.
I would see meds as the last resort.
tg