i have a 13 year old son that rides a 03 p650.he started out on a kx 85 doing motor cross and moved up to the 650 when he got to old to race our local track. He rides with us and we all have 650 or bigger bikes and he keeps up fine.He can handle the bike just fine. so get your dad to ride one before he makes up his mind for you.

 

I couldnt see a kid riding a 650. Im good buds with the local dealer, he says a kid could handle a 360 but a 650 is just way too much power for a kid, especially a girl. But hey, get what you want. My 360 fits me just fine.