and known as Daisy, she was the only daughter of Isabelle-Blanche Singer (1869-1896) and Jean Élie Octave Louis Sévère Amanien Decazes de Glücksbierg (1864-1912), 3rd Duke Decazes and Duke of Glücksbierg. Her maternal grandfather was Isaac Singer, the American sewing machine pioneer. After her mother's suicide, she and her siblings were largely raised by their maternal aunt, Winnaretta Singer