[4] She studied the piano from the age of nine, and afterwards entered the Albert Street Conservatorium for singing and voice production and obtained the full diploma.

Her Sieglinde (Die Walküre), often performed opposite Kirsten Flagstad's Brünnhilde, won its own individual triumph, and resulted in an invitation to appear as a guest artist in the Rome Opera International season, where she made her debut as Sieglinde in March 1952 under Erich Kleiber, and sang the role several times during the season.

[8] In March 1954, Fisher married Ubaldo Gardini, an Italian-born violinist who worked at Covent Garden as an Italian language coach.

She visited Australia, performed in the United States, then returned to England where she worked for Covent Garden's rival, the Sadler's Wells Opera Company from 1962 to 1973.

[6] By 1955 she had made appearances in Beethoven's Missa Solemnis and Choral Symphony, Verdi's Requiem, Delius's Mass of Life, Rossini's Stabat Mater, Arnold Schoenberg's Gurre-Lieder (Tove), and the concert performance of Paul Hindemith's Mathis der Maler.