Maria Pavlovna the Younger and her brother Dmitri. According to Wikipedia, there are her memoirs, and multiple biographies, but I couldn't say whether any of them are any good.

It looks like there'd be enough material for one of those historical trilogies, with the covers featuring women in mostly period dresses and improbable hair turned away from the viewer and a tagline like Duty...Passion...Revolution. I am absolutely not volunteering to write it.