I just bought a Trek 7300 step-through ladies frame. I am OK with the 16". I have an Adams Trail a bike to hook on the back for my 6 year old. This is a great bike. Too bad they don't have more frame sizes.
Just a note to anyone looking for a step-through frame. I was thrilled that the 7000 series is offering this. I love the bigger, pavement friendly tires, and since we also bought one for my mom who has hip problems, the step-through frame was a must. As far as I could find, Trek was the only brand that offered the larger diameter tire with this frame option.