Hiya fellow vertically efficient rider
I'm 5'2", and I can echo a lot of what the others have said -- esp. the part about most of it being a new rider. I actually backed out of having my ninja lowered and am still riding stock and after a while 'figured it out'. A corbin seat is on my 'todo' list though, just for extra comfort.
You may also like this youtube video I saw when I was considering what to do with my new ninja (and it is by a fellow ninjette-r as well):
Link to original page on YouTube.