[3] She was the niece of Adolf II, the last ruler of the Principality of Schaumburg-Lippe who abdicated following the German Revolution of 1918–1919.

[1] Marie Alix's younger brother, Prince Georg Moritz of Schaumburg-Lippe, was killed in a car accident in 1970 without marrying or having children.

[1] Marie Alix married Peter, Duke of Schleswig-Holstein, third son of Wilhelm Friedrich, Duke of Schleswig-Holstein and his wife Princess Marie Melita of Hohenlohe-Langenburg in Glücksburg on 9 October 1947.

[3] Peter and Marie Alix had four children:[1] She was a co-founder of the Stiftung Louisenlund, which runs an eponymous boarding school in Güby, Schleswig-Holstein, Germany.

[3] Princess Marie Alix of Schaumburg-Lippe died in Thumby on 1 November 2021 at the age of 98.