Sister of the German philosopher Friedrich Nietzsche, who became his guardian and literary executor.
An early believer in the superiority of the Teutonic races, she married an anti-Semitic agitator, Bernhard Förster. They planned to create a “pure” Aryan settlement in the New World, and had found a site in Paraguay which they thought would be suitable. The couple persuaded 14 German families to join them in the colony, to be called Nueva Germania, and the group left Germany for South America on 15 February 1887.
The colony did not thrive. The land was not suitable for German methods of farming, illness ran rampant, and transportation to the colony was slow and difficult. Faced with mounting debts, Förster fatally poisoned himself on June 3, 1889. Four years later his widow left the colony forever and returned to Germany. The colony still exists.
She served as Nietzsche’s guardian at Weimar after his mental breakdown in 1889. On his death (1900) she secured the rights to his manuscripts and renamed her family home the Nietzsche-Archive. Refusing public access to her brother’s works, she edited them without scruple or understanding.
While Elisabeth gained a wide audience for her misinterpretations, she withheld Nietzsche’s self-interpretation, Ecce Homo, until 1908. Meanwhile, she collected some of his notes under the title “Der Wille zur Mach”t (“The Will to Power”) and presented this work, first as part of her three-volume biography (1895–1904), then in a one-volume edition (1901), and finally in a completely remodeled two-volume edition (1906) that was widely considered Nietzsche’s magnum opus. Her distortions of Nietzsche’s ideas in this work and others were in large measure responsible for the subsequent misperception of Nietzsche as an early philosopher of fascism. Elisabeth was a supporter of the Nazi Party.
She died 8 November 1935, Weimar, Her funeral was attended by Adolf Hitler and other Nazi dignitaries. After her death scholars reedited Nietzsche’s writings and found some of Elisabeth’s versions distorted and spurious: she forged nearly 30 letters and often rewrote passages. The discovery of her forgeries and of the original texts profoundly influenced later interpretations of Nietzsche’s philosophy.

Link to Wikipedia biography