She won a Leverhulme scholarship to the Royal College of Music, where she was a pupil of the violinist Isolde Menges.
During her time there she turned from the violin to the viola, and studied with the violist Ernest Tomlinson.
[1][2] In 1941 she was recommended by Ivor James, her chamber music teacher at the Royal College of Music, to the Menges Quartet (founded by Isolde Menges), to stand in for their regular viola player who was ill; she became their permanent violist.
[1][3] Ralph Vaughan Williams dedicated to her his Second String Quartet in A minor, with the words "For Jean on her birthday".
In a letter to Vaughan Williams, after receiving the music and before the performance, she wrote "Without exaggeration this Quartet is the most lovely thing that has happened to me in my life".