Even on into the 1920's, there are tons of examples of woman intentionally painted as thick, muscular and robust. These are industrious women. It is not a matter of lack of slender models, rather it is showing these women as a force of nature - someone to be reckoned with. From a mythical Muse, to a supernatural female being, to a successful women on her farm. It conveys power - significance. Example: https://live.staticflickr.com/39/104396309_9a2ba1dcea_b.jpg