Her father Gabriel Osmund Jacques Blaise de Sibour (Cannes 8 April 1896- 22 April 1979, Lisbon) was from a Franco-American family and an aviation enthusiast. Her brother Jean de Sibour born in London, 29 January 1922, was a pilot in the famous Normandie-Niémen squadron and his plane was shot down on 31 August 1943 in the Ielnia region, Smolensk, Russia, USSR.