World War II postponed her acting career, and she did not make her stage debut until 1945 with the Birmingham Repertory Theatre, working under director Barry Jackson.

At the close of the war, she quickly became a regular presence on the West End, making her debut in 1946 as Lynne Hartley in Warren Chetham-Strode's The Guinea Pig at the Criterion Theatre.

Several of her stage appearances were broadcast live on television on the BBC Sunday Night Theatre including The Tragedy of Pompey the Great (1950), The Doctor's Dilemma (1951), and Eden End (1951) among others.

Her television credits at this time included Night River (1955), The Scarlet Pimpernel (1956), Colonel March of Scotland Yard (1956), Our Mutual Friend (1958) and The Moonstone (1959).

[2] On the stage she starred opposite John Gielgud as Hermione in the 1965 production of A Winter's Tale and as Lady Chiltern in An Ideal Husband at the Piccadilly Theatre in 1966.

Her television credits include Dixon of Dock Green (1961), Katy (1962), The Saint (1963), Compact (1963), ITV Play of the Week (1964), Game for Three Losers (1965), The Wednesday Thriller (1965), Mystery and Imagination (1966), The Rat Catchers (1966), Armchair Thriller (1967), The Portrait of a Lady (1968), ITV Saturday Night Theatre (1969), The Way We Live Now (1969), Upstairs, Downstairs (1971–1973), Dangerous Corner (1974) and Fall of Eagles (1974).

In 1977, Gurney made her American stage debut off-Broadway as Mrs. Clandon in George Bernard Shaw's You Never Can Tell at the Roundabout Theatre in New York City.