Dear Dario, you’re right: the Ninja (in the foreground of the photo, ridden by one of our young testers) is really the least tall of the 125 sports bikes, with its 791 mm (measured data) at the saddle. The naked Z125 cousin sports the same height.
Excluding the custom ones, the lowest 125s are the vintage ones: Mash declares a 760 mm saddle for the Seventy, while the Brixton Cromwell reaches 770 mm. Next come the naked, with the Benelli BN 125 sporting a saddle at 780mm from the ground and the Suzuki GSX-S, measuring 786mm. Just one millimeter more for the SYM NH-X. With the Honda CB125F and Rieju Century both claiming 790mm, we skim over which Ninja figure your girl would want.
Bear in mind that, in general, the measured data is a few millimeters higher than the declared one and that the height of the saddle says a lot, but not everything. In fact, the width of the “hips” also counts: the narrower they are, the easier it is to put your feet on the ground.
You are therefore doing very well to visit the dealerships to check the real roominess of the bikes in the field.