Sounds like your girlfriend should adopt a low
carb diet, in order to reduce incidences of blood sugar
cycling up and down. The more stable the blood sugar level, the less cycling up and down, which is causing her to feel sick. It's hard to manage insulin and medications to counteract ingesting large amounts of carbohydrates. So, if she stops eating high amounts of carbs, less need to counteract with meds. Try a day in two low carb, and you will see the difference.