Jarred was born in Brotton, Yorkshire, (now in Redcar and Cleveland), and studied at the Royal College of Music.
On the recommendation of Lauritz Melchior, she was invited to the Hamburg State Opera and remained there as a guest artist for the following three years.
Her roles included the Nurse in Richard Strauss's Die Frau ohne Schatten and several in contemporary works by Hans Pfitzner and Alban Berg.
[1] In 1934, she sang Margret in the first British broadcast performance of Alban Berg's Wozzeck for the BBC, conducted by Adrian Boult.
[2] Along with Eva Turner and Roy Henderson, Mary Jarred took part in a BBC Radio broadcast written and presented by John Steane in 1989 celebrating the 50th anniversary of the Serenade to Music.