Helena married on 26 October 1921 in
Arolsen,
Nikolaus, Hereditary Grand Duke of Oldenburg (1897–1970), They had nine children: •
Anton-Günther, Duke of Oldenburg (16 January 1923 – 20 September 2014); married
Princess Ameli of Löwenstein-Wertheim-Freudenberg, had issue • Duchess Rixa of Oldenburg (28 March 1924 – 1 April 1939); died unmarried and without issue • Duke Peter of Oldenburg (7 August 1926 – 18 November 2016); married Princess Gertrude of Löwenstein-Wertheim-Freudenberg, had issue • Duchess Eilika of Oldenburg (2 February 1928 – 26 January 2016); married
Emich, 7th Prince of Leiningen, had issue, including
Prince Karl Emich of Leiningen and
Andreas, Prince of Leiningen • Duke Egilmar of Oldenburg (14 October 1934 – 10 May 2013) •
Duke Friedrich August of Oldenburg (11 January 1936 – 9 July 2017); married first Princess Marie Cécile of Prussia, had issue, second Donata Countess of Castell-Rüdenhausen, no issue • Duchess Altburg of Oldenburg (b. 14 October 1938 - 30 October 2025); married Baron Rüdiger of Erffa, had issue • Duke Huno of Oldenburg (b. 3 January 1940); married Countess Felicitas-Anita of Schwerin von Krosigk, had two daughters including
Beatrix von Storch • Duke Johann of Oldenburg (b. 3 January 1940 - 5 April 2025); married Ilka Gräfin zu Ortenburg, had issue. His daughter
Eilika married
Archduke Georg of Austria She died at the age of 48, her husband married again, two years after her death in 1950 to
Anne-Marie von Schutzbar genannt Milchling. ==Ancestry==