She started her professional career with Ralph Richardson as Dolly in Bernard Shaw's You Never Can Tell and Lucy in Sheridan's The Rivals followed by Cecily in "The Importance of Being Earnest" at the Theatre Royal, Haymarket, London.
[1] She played a number of major television roles early on in her acting career notably Elizabeth Bennet in Pride and Prejudice[2] (1967), Cecily in The Importance of Being Earnest and Lady Diana Newbury in Upstairs, Downstairs.
[4] Bannerman was Associate Director at the Bristol Old Vic directing The Price, Translations, Quartermaine's Terms, The White Devil, Good Fun and La Ronde.
She was the Staff Director at the Royal National Theatre on The Passion, Larkrise, Fruits of Enlightenment and Strife.
Also for Sands Films she cast "The Fool", "As You Like It" and "A Dangerous Man: Lawrence after Arabia" which won an Emmy for Best Drama.