Remember she was wearing corsets.
Yes. But even if you are wearing a corset, it cannot make your arms thinner. And in this pic, Miechen's arms are those of a rather thin person. If you wants to know if a woman from back then was slender or it's the corset who is fooling your eyes
, just look at her arms. If they are quite thin, it's probable that the woman was also thin. If not, you'll notice a woman with a little waist and enormous arms...
You must also remember that back then, corsets were worn not only for women waist looks thinner, but to keep their figure well-shaped. Some girls would even sleep wearing their corset just to keep a slender figure. They would wear it as nowadays "modelators" (I don't know how to say it in English, I mean like modern corsets to shape your figure). Just think almost all woman back then would wear corsets, slender or not.
RealAnastasia.