My youngest son grew up racing motorcycles and quads on dirt, and me and his 3 older brothers all ride so I knew as soon as he could he would be riding street bikes too.
When he was 13 I bought him a Ninja 250 and began taking him with me on my country rides, we are fortunate to live on a great riding road with lots of hills and curves.
He rode the Ninja until he was 15 when I got a good deal on a CBR600RR, so I moved him to that and continued riding with him making sure he learned good judgement and technique.
He got his license in June and the picture below is him and two of his brothers less than a week after he was legal, he couldn't wait to go to the Dragon with his brothers and I on our yearly trip.
He still has the 600 but also has an FZ1 he got a few months ago, he rides all the time, and of course it makes you a little nervous when they are out riding but just take the time to teach them right and get them the experience they need.