Lengefeld was born in Rudolstadt, Schwarzburg-Rudolstadt, into an aristocratic family, and given an education appropriate to a life at the ducal court of Weimar.
[1] Her father Carl Christoph von Lengefeld [de] (1715–1775), who died when she was a young girl, had been a forest administrator of Louis Günther II, Prince of Schwarzburg-Rudolstadt, while her mother was Louise von Lengefeld [de], nee Wurmb (1743–1823).
They began a correspondence in 1788, and, aided by the Lengefelds, Schiller took up residence near Rudolstadt shortly thereafter.
In Caroline's later novel Agnes von Lilien, two women both pursue a relationship with a young baron, and critics have debated whether to understand the novel's love triangle as a reflection of Caroline, Charlotte, and Schiller (more recent critics are less inclined to do so).
Her letters to her husband, her sister, Stein, Goethe, and others have been published in multiple editions.