Encourage them to wear trail runners. Parents should like this because its a footwear they can actually get more use out of, wear around town, to school, etc.
It is amazingly hard to dissaude people from the heavily ingrained stereotype that you have to have boots to go outdoors. Thats all it is, an image, and marketing.
Boots are great for tramping thru heavy brush, sticks, debris, puddles. They simply arent needed on most trails.