I have 4 kids.
My oldest son started on his 5th bday. Hes 17 now. XR50,RM80,LTZ400,LTR450, now on his KX250F.
Next son started on his 5th bday. Hes 6 now. Yamaha 50 bike, Raptor 50, now looking for a Raptor (or any brand) 90 ATV
Next is my 4 yr daughter. Next yr is the year.
Then my 22 month old.
Pretty much on there 5 th bday we introduce them to offroading with a real machine. They all started with the powerwheels around 2yrs old.
Ive seen some 4 yr olds that were bigger than my kids at 5. Its all about what they can handle, mind set,size,etc.
Ive seen tons of 10,11 hell even 12yr old children that have NO BUSINESS ON A MACHINE. They are goin to severly hurt themselves cause they arent ready and havent been taught correctly.
They need to know what you say goes. If not, there not ready.
To the OP. I think its great your introducing your little one to the sport. We need this. Good luke on your search. And please post up what you get'm. We all love pics.