I love my 599 too! It's a fabulous bike for a woman, I think - fairly low and lightweight, but plenty of power - a good combination. I've rarely been anyone's passenger though. I started riding back in 1986, on a 500cc Honda Shadow, and have been riding ever since. I couldn't take the riding position so soon moved on to standards (Guzzis, mostly) and old Brit twins.
There are plenty of women riders if you know where to look. Women in the Wind, Ladies of Harley, WIMA, Women in Sport Touring, etc, are all out there.