Born in 1890 in Sèvres (Seine-et-Oise, now in the Hauts-de-Seine),[REF] Claire Bertrand is the daughter of Marcel Bertrand geologist and Mathilde Mascart, a talented pianist; she is the granddaughter of the mathematician Joseph Bertrand [REF].
Arrested in 1914 as an Austrian subject, her husband was detained in an internment camp during the beginning of the First World War.