You've raised a couple of interesting points.

Shoes?

If I may make a pointed comment, it is easy to flesh out that this young lass is keeping abreast of jazz age bathing fashions.

To react to those last two words. Well, next to last, actually.

I always thought that phrase from "All That Jazz" in the musical "Chicago!" was a strange lyric.

Rolling down your stockings was a way of being sexy - women's legs were still considered risque in a time when long skirts were still being worn. To show your legs was the equivalent of today wearing a micro-mini skirt and bikini top.

In the 1920's, rouging one's knees was a popular make up fad. Some women used rouge to highlight and draw attention to their cheeks, although modest women resisted the use of make up and preferred to make the most of ‘natural’ beauty instead.

Flappers, on the other hand, thought of themselves as promiscuous and sexy rebels, and so they rouged their knees to draw attention to them.

I'd never actually seen it until this picture. Thanks, Shorpy!

Thin loose fitting clothing without the assistance of upper support was the style in the 20s/very early 30s. Check out some of the silent and early talkie motion pictures. Young ladies always looked like they were about to have wardrobe malfunctions.

Jazz Age edition

I can see right through your explanation of the photo. Very witty indeed.

Wait -- they had those then?

and she is beautiful, with those dark eyes. She also has hips, a facet of womanly beauty that seem to be hidden by today's fashions.

And, I repeat I know this is a family site, but did the beauties of that era also go without upper body undies?

Exposure of those knees leaves very little to the imagination.