Working for family businesses is explicitly exempted in the states I'm aware of. A friend of mine made good money working for his parents' bait and tackle shop. It was tax-exempt, too!
From what I remember, when I was 14 I also worked for a large landscaping company (35-70 employees) they would have been happy to let me run the big mowers, however they weren't legally allowed to.
I spent as much time mowing lawns as most of my classmates spent playing sports. That isn't outlawed. I still went to school
