DS's preschool report card listed that he has not met certain gross motor milestones, such as pedaling a tricycle and riding a scooter. Do those skills emerge even if the child does not own either those items? DS only has a balance bike (which he just got a few months ago). He's never ridden any bike with pedals or a scooter other than last Fall at school. And when he does, it's only a couple minutes at a time because the kids get one lap and then they have to give the bike to the next person. The teacher says he is okay on the straightaway, but when he has to turn, he loses momentum and slowly pushes the tricycle with his feet through the turn. (meanwhile the other kids waiting in line are yelling at him to hurry up!) Do I need to even worry about this?