Petr) Excellent observation and one that I was just discussing recently with another member on the AP.
I think one of the reasons why we are so fascinated with the women living during the time period of the late-19th and early-20th century is because it was a very transitional period. Changes in political alignments, customs, social attitudes, technology, etc, were all so abundant...perhaps moving too quickly for some, but many of the most interesting figures from this era seem to be the most progressive ones.
With regards to an elegant women such as your grandmother I think they provide not only the necessary historical context but a bridge between two very different eras...Victorian era (ending 1901) to the modern era (arguably began at the end of WWI). In the nearly two decades in between we saw rapid change...defined by war and revolution in Russia/eastern Europe, the "Edwardian" era giving way to WWI in Britain and a lengthy "Progressive" era in the United States. I'm in awe of these women...their ability to adapt to a rapidly changing world, still confined to social structures & victims of prejudice & stigma (full suffrage didn't come about until 1920 in the U.S., for example), and yet do so with a graceful dignity worthy of their predecessors.
I also agree the "admirable quality", as you put it, has largely been lost over time. The liberalization of attitudes and social structures have leveled the playing field in many positive ways. Any decent person surely wants to live in an egalitarian society where the potential for all to succeed exists...regardless of gender, race & background. But the eliminating of traditional roles in society, while surely altruistic, I believe has also stripped away some of the great personal qualities you have talked about. We get caught up in the day to day competition of the more universal human rat race. Subsequently I feel like people in modern times have begun to work harder (or at least forced to be more innovative) at their jobs and output, but have grown collectively lazy when it comes to working at their personality and public image.
We strive for a "classless" society...but that also means we live in one of less class...