Förster-Nietzsche was two years younger than her brother. Both were children of a Lutheran pastor in the German village of Röcken bei Lützen. The two children were close during their childhood and early adult years, but grew apart when Elisabeth in 1885 married Bernhard Förster, a former high school teacher who had become a fanatic anti-Semitic agitator. Förster planned to create a "pure" Aryan settlement in the New World, and had found a site in Paraguay which he 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 February 15, 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 wife left the colony forever, and returned to Germany. The colony still exists.
Friedrich Nietzsche's mental collapse occurred in 1889 (he died in 1900), and, when his sister returned for good, he was an invalid whose published writings were beginning to be read and discussed throughout Europe. Förster-Nietzsche took a leading role in promoting her brother, but distorted parts of his philosophy, especially through her edition of Friedrich's posthumous fragments under the name of The Will to Power.
In 1930, Förster-Nietzsche, a German nationalist and antisemite, became a supporter of the German National Socialists. After Hitler and the National Socialists came to power in 1933, the Nietzsche Archive received financial support and publicity from the government, in return for which Förster-Nietzsche bestowed her brother's considerable prestige on the régime. Förster-Nietzsche's funeral in 1935 was attended by Hitler and several high-ranking National Socialist officials.