expect biketech to give you a smart ass answer. lol at thaking

but seriously i would narrow it down to the 600s... mainly the cbr600 or the zx6r. she might find the yamaha way too aggressive of a stance.

if i were to pick between the zx6r or the cbr, i would pick the cbr. take note of the seat stance and the seat comfort. i found more comfort with the cbr, plus i think the cbr has a better suspension than the zx6r. (my opinion only).