I don't remember the specs and they're not online any more, but I do remember that the men's version of my Synapse - which is the same as yours - had at least a 1.5 cm longer top tube in the same model year.

Now, the seat tube angle and the setback it requires might obviate the shorter top tube. But the frames weren't identical, I remember that for sure, because I spent a good amount of time poring over the specs. There wasn't much difference at all between the Spec' Ruby that I'd test ridden and knew would fit, vs. the C'dale Synapse Feminine that I didn't get a chance to test ride but bought anyway.