Short answers, pulled from the story.
Stéphanie de Beauharnais was a French princess born in Versailles on the 28th of August 1789, related to Napoleon's wife Joséphine through the de Beauharnais family. Napoleon adopted her and named her "Princesse Française" with the style of Imperial Highness so she would have sufficient rank to marry into the ruling house of Baden, securing a diplomatic alliance with the Prince-elector.
Stéphanie de Beauharnais married Karl, Grand Duke of Baden, in Paris on the 8th of April 1806. Karl succeeded to the title of Grand Duke on the 10th of June 1811 after his grandfather Karl Friedrich died.
Stéphanie was the daughter of Claude de Beauharnais, 2nd Count des Roches-Baritaud, whose first cousin was Alexandre, Vicomte de Beauharnais. Alexandre was the first husband of Joséphine, who later married Napoleon on the 9th of March 1796. Eugène and Hortense de Beauharnais, Napoleon's stepchildren, were second cousins of Stephanie.
Stéphanie de Beauharnais and Karl had five children. Three daughters survived to adulthood: Luise Amelie Stephanie, Josephine Friederike Luise, and Marie Amelie Elisabeth Karoline. Two children died in infancy: an unnamed son in 1812 and Prince Alexander of Baden, who lived only one week in May 1816.
Stéphanie de Beauharnais died in Nice, France, on the 29th of January 1860, at the age of seventy-one. She had outlived her husband Karl by forty-one years.
After Karl died on the 8th of December 1818, Stéphanie remained a widow in Mannheim for the rest of her life. Her residence became a well-known salon for artists and intellectuals, and she was regarded as a devoted mother to her three daughters.