Having 4 traditional styled (Stillwater and Frugal) kilts with wide aprons and 2 DIY and 3 UK mockers with narrow aprons, I agree with your wife's viewpont as regards looks and of course, of even more importance, the narrow arpron is much more practical than the traditional style when I am playing my cello in public and do not wish to be accused of flashing.
Phicong, the sassenach.