Our oldest girl just turned 13 last weekend, and shows no interest or aptitude for driving anything. Youngest boy, at 7, wants to drive everything, and I'd let him if he was big enough to do it. I could see him running the kubota next summer, being hst, he should be able to handle it. (Hes 'got it', always has, even as a toddler on a battery powered toy in the house.) I'll let the girls do so also, if the interest is there. I started running my dad's mf135 at 8, and will follow in his footsteps with my kids, training them to operate things safely, and respect what equipment can do to you and for you.