Actually, glasses will stay on just fine when running. I used to have glasses as a kid (I wear contacts now) and I didn't have any problems at all with my glasses on in PE class. Do make sure her glasses fit properly (not to tight or too loose at the ears). Usually the optometrist's office will make those adjustments for free, so if her glasses are too loose then she should stop in the optometrist's office. The way to check if they're too loose: she should lean over forwards bending at the hips until her back and head are parallel with the ground. If her glasses fall off to the floor, they're too loose. Do not, however, make the mistake of having them be too tight at the ears. Loose-ish fit is better so long as they don't actually fall off if she bends over. If they're too tight it will be extremely irritating to wear them all day, so be careful. As a first-time glasses wearer, she should not be shy about getting them adjusted at the optometrist's office - it may even take a few trips there at first until the 'perfect' fit is found.