What Causes Dizziness Along With Headache?

My 10 yr old daughter, 100 lbs, 5ft tall, premenstrual, has been for the past 2 months experiencing dizziness, sometimes followed by a headache. She's been to the dr twice and the dr feels it's her eyes. We just had her eyes checked and they did get worse, so now she is wearing her new glasses and is still dizzy. She is get anxiety about it and afraid to go to school b/c of having these spells and our school nurse is not the nicest. She takes claritan daily b/c i thought possibly allergies, but no change. She was also having nausea but that seems to have stopped a bit w/ the pepto, she does have reflux as well. Could this be a migraine related thing or the fact that she's premenstrual?