I've met 100lb girls that could ride a 600cc better than every s.q.u.i.d. on the road. That being said they started much smaller and worked their way up. Next time start on a moped, then a scooter, then maybe an old 125cc.
As long as your o.k. and lil sis learned to respect (not completely fear) those bikes it'll be alright in the end.
On another note seen the same thing with two idiots on a FL beach. End result hydrolocked motor
