I have a child that has been around horses all of their lives. I rode with them at just 6 months old. They rode whenever I did. Now that I am showing my oldest wants to do walk trot with my 5 year old paint mare. Yes I know in general you want the age of the child and the horse to be 20. She has always been really gentle with my boys and takes good care of them when they ride her.
I have just started now letting my oldest one ride. I am giving him lessons so that next year he can show her in walk and trot classes. I still have him on the lunge line but I have just started him riding alone two weeks ago. He can get her to stop, turn, walk, and trot when he tells her to. I have her working off of voice commands and cues from the legs as well.
You know your boy more than anyone else.
Striving to always excel in everything I do. Whether I fail or not I always try to do better than last time.