[1][2] Born in Johannesburg, South Africa, Cruddas moved to England with her parents when she was an infant.
At the end of the conflict she began to design costumes for the theatre and was quickly talent spotted by the dancer and actor Sir Robert Helpmann.
Cruddas' first commission was designing costumes for The White Devil at the Duchess Theatre, London (1947).
Other early career highlights were for John Burrell’s 1947 Old Vic production of Taming of the Shrew and Verdi's, Aida at Convent Garden (1948).
At Bardfield she became involved with the dynamic art community which included: John Aldridge, Edward Bawden, George Chapman, Stanley Clifford-Smith, Joan Glass, Walter Hoyle, Sheila Robinson, Michael Rothenstein, Marianne Straub, among others.