If she has an allergy to gluten, this could cause symptoms such as diarrhea, rash, gas, abdominal pain, delayed growth-shortness, fatigue, and weight loss and vomiting. I would stick to what the doctor says with the restricted food diet and follow up with the doctor because your grandchild could become dehydrated or even worse if she is vomiting that much almost everyday. A little one shouldn't have to go through all that.
What food items is she allergic to? Please sate her weight (in kg or lbs.) and height.
Thank you