By 1937, some young women were wearing pants to play golf—but not these two. It looks like their mother had brought for a day on the course. Did she play as well? If so, she has on the wrong shoes.
What constituted sportswear for these golfers? It looks to me like they are have on knit skirts, a fabric with a lot of stretch. They also wear sweaters, the two on the left in cardigans and the one on the right in a pullover with a sporty collar. Everyone has on hats, with the one on the right—perhaps the tomboy in the family—wearing a baseball hat. They are in sturdy shoes with short socks.
The older woman is dressed very similarly to the younger ones, although her skirt is longer, her hat fancier, and her socks darker. Was she a former golfer who had given it up? And is sportswear one area where the dress of the old and young sometimes converge?