PORTRAIT OF FOUR OLDER WOMEN AND TWO YOUNG (NUNS?) OR (NURSES?) For Sale

This vintage real photo postcard raises a lot of questions but not a lot of answers. On the surface, this looks like a portrait of four older women and two younger women dressed like nuns. The older women have a strong family resemblance and I am hypothesizing that they are sisters. Taking a closer look at the image, I can not be certain that the younger women are nuns. Their clothing looks more simple then I typically see in portraits of nuns of that era. However, there certainly could be cultural differences, as well as order differences, in regard to the habits worn by nuns around the world. I also question whether a nun, such as one of the young ladies in this portrait, would be wearing a pin, presumably attached to a pocket watch. I am also uncertain whether it would be expected that the two young ladies in this image are wearing closely similar, but not identical “habits”. Is it possible that the two “nuns” are actually “nurses”? This portrait postcard was “found” in Vancouver, Canada. However, it was part of a collection of Scottish images. This real photo postcard is in excellent condition (see scans).