Carol
Try to make sure your child gets enough water. This used to happen to me when I was younger and I never knew why. As an adult, I get migraines when I don't drink enough water. I can head them off with the water. I have fairly low blood pressure and used to get dizzy standing up at times if I was dehydrated. I would suggest a tall glass of water at every meal (not anything with caffeine or milk) and see if that helps.