But it's a good theory, it's reasonable and there is evidence to back it up.
Married women were almost always (in a studio setting anyway) posed to show off a wedding ring. Even older women. So if a woman is photographed with her left hand out of view (and we've seen some odd, contrived poses) or even covered with a bit of dress or flowers, we may surmise that she isn't married.
See, Jim does take his meds once in a while

Cheers,
China