The sixth of seven children and the third of four girls, Margarethe Sylva Elisabeth Schlegel was born at 11:45pm on 31 December 1899 in Bromberg, West Prussia, German Empire, (present-day Bydgoszcz, Poland) to a German-speaking Prussian-Polish Catholic family.

Naturally beautiful and talented (she could sing, dance and act well from an early age), Schlegel sought a chorus role in theatre in 1917 as a way of earning extra money for her family while still a schoolgirl due to the privations of war.

When her husband was dismissed from his professorship at the Technische Hochschule in Charlottenburg (now Technische Universität Berlin) in May 1933[1] and his academic books and novels written under the pseudonym Hermann Lint were burned by the Nazis, he travelled to Britain to give the Sidney Ball Memorial Lecture at Oxford University[2] and as a visiting professor at King's College, Cambridge at the invitation of the Professor of Economic History, John Clapham.

At about the same time, her husband was added to Hitler's so-called Black Book,[3][4] the death list of opponents of the Third Reich who would be arrested upon the anticipated Nazi occupation of Britain after Operation Sea Lion.

Also in 1938 her husband's former family residence and marital home in Tiergarten, "Villa Kabrun", was seized by the Nazis for use as the foreign embassy of the Kingdom of Yugoslavia in the putative "world capital", Germania.