I won't say much about the helmet because I have never worn one. BUT, if the kid is not old enough to stay on under his own power and steer and stop the horse himself, then they need to have someone leading the horse. I was on horses as an infant but I was always with my Dad. He would take me to warm up his show horses and sit me in the saddle in front of him. I got my own horse to ride by myself when I was 4 but I still had my fair share of falls. Bombproof or not, there is always 1 more thing that horses are scared of.