[4] His Swiss friend Marguerite Respinger (1904–2000), whom he had met when he was studying in Cambridge and had invited to Vienna, was briefly (1926–1931) the only known female interest of Ludwig Wittgenstein.

Her second son was Major John Jerome Stonborough (11 June 1912 - 29 April 2002), who, although a US citizen, served in the Canadian Army during Second World War as an intelligence officer and interpreter.

When working in juvenile prisons as a psychotherapy adviser, she came into contact with Sigmund Freud and was analyzed by him over the course of two years.

[5] In 1926, she commissioned her brother Ludwig and the architect Paul Engelmann to design and build Haus Wittgenstein in Vienna.

[6] In 1940, she emigrated to the US, but returned to Austria after the war and obtained restitution of part of her wealth that had been confiscated by the Third Reich.