Well done Herb, very interesting thread and I was going to start EXACTLY the same topic myself, last week.
As an ex-motorcycle instructor and examiner, I'd love to be able to take my 7 year old daughter for a ride on my Ducati (but if so, only with the proper clothing, helmet etc).
However, if anything happened and she was injured by either my mistake or not - I dont think I'd be able to cope with that and it could well end my road riding. The sad thing is, I know she would enjoy riding pillion but until she is old enough to make a reasonably informed decision of her own, I feel the risk is unnacceptable on today's roads.
Good job she is enjoying having a go at quad bike riding at a local facility, maybe she can get into rear end sliding before becoming the first female to win a MotoGP
Cheers - Frank