She was born as Sybille Aleid Elsa von Schoenebeck in Charlottenburg, west of Berlin, to Maximilian Josef von Schoenebeck (1853–1925), a German aristocrat, retired lieutenant colonel and art collector, and his German Jewish wife, Elisabeth Bernhardt (1888–1937). Sybille was raised in the Roman Catholic faith of her father at Castle Feldkirch in Baden. She had a half-sister by her father's first marriage to Elisabeth Marchesani, Maximiliane Henriette von Schoenebeck (later Baroness von Dincklage, aka "Jacko" or "Catsy"). Her parents divorced in 1918, and she remained with her father, under somewhat impoverished circumstances in the midst of his art and wine collection. He died in 1925, when she was 14 years old, and Sybille went to live in Italy with her mother and stepfather, an Italian architectural student. During those years she studied in England, lodging in Hampstead.