Marie Rambert and the last changed his name to Warszawski. She changed her name to Myriam Ramberg, and finally left it in the French form "Marie Rambert". In later years she was known to friends and dancers as Mim. Her father, Yakov Ramberg (1855–1928), born in Vištytis, a small town in Suwałki Governorate (nowadays in Lithuania), was a learned merchant and Hebrew publisher and lexicographer, and a Zionist. Her mother, Eiga Ramberg née Lap, born in the town of Suchowola (nowadays in north-east Poland), daughter of Rabbi Elhanan Tzvi Lap, was a community worker. Rambert was the fourth of seven children. The
Joan Denise Moriarty and his wife, Marion (née McCarthy); John Francis Moriarty, Lord Justice of the Court of Appeal in Ireland, was her uncle. The Moriartys were originally from Mallow, County Cork, where her grandfather John Moriarty was a successful solicitor. Moriarty was brought up in England, possibly in Leeds, or Liverpool, where she was living in the 1930s. She studied ballet until her early teens with Dame Marie Rambert. How long she was enrolled in the Rambert School is not known, as there are no records of students, but only of performers, but her training there was referenced by Dame Ninette de