My daughter is three years old and we have spent most of our summer outside. I am good about putting sunscreen on my kids and lucky they have good skin. 4 times this summer after playing most of the day outside, my daughter has woken up about 10PM throwing up in bed. She would throw up and then be completely fine. Never sick, no fever. Any idea what this may be? The food she eats those days are not different from other days.