Princess Stephanie of Windisch-Graetz's mother was a member of what political party?
Archduchess Elisabeth Marie of Austria Archduchess Elisabeth Marie of Austria (Elisabeth Maria Henriette Stephanie Gisela; 2 September 1883 – 16 March 1963) was the only child of Rudolf, Crown Prince of Austria and Princess Stéphanie of Belgium, and a granddaughter of Emperor Franz Joseph I of Austria and King Leopold II of the Belgians. She was known to the family as "Erzsi", a diminutive of her name in Hungarian. Later nicknamed "The Red Archduchess", she was famous for becoming a socialist and a member of the Austrian Social Democratic Party.
Princess Herzeleide of Prussia Princess Herzeleide-Ina-Marie Sophie Charlotte Else of Prussia (25 December 1918 – 22 March 1989) was a member of the deposed House of Hohenzollern. She was the only daughter of Prince Oskar of Prussia (the second youngest son of Emperor Wilhelm II) and his morganatic wife ,Countess Ina Marie von Bassewitz. She is the mother of Ernst-Johann Biron, Prince of Courland, the current head of the House of Biron.