I am from Connecticut , then NH & now Fla. I have two daughters. They both rode with me (on "chopped" Triumphs) before they were 10! My oldest daughter just came for a visit in Fla. The 1st thing that she did was to get out of my wifes car (from the airport) & jump on the back of my bike before even going in to unpack! My Grandson (her son) also rode with me on a visit so I don't see the problem if you start them young. If they like it (some don't) they will continue riding.
Irish