She is best known to today's audiences as "Lady Ada Epping" opposite comedian Leon Errol in the Mexican Spitfire movie comedies of the 1940s.

[1][4] She appeared at the Comedy Theatre in December 1907 as Tiny Montague in Angela, a farce by Georges Duval and Cosmo Gordon-Lennox, starring Allan Aynesworth and Marie Tempest.

[1] Between September 1900 and October 1910 Bilbrook was in five West End productions – as Helene in Madame X, Mrs Otto Rosenberg in Smith, Ethel Morley in The House of Temperley, Adele in A Bolt from the Blue, and Odette de Versannes in Inconstant George.

[1] In September 1911 she appeared as Stephanie Julius in the comedy The Great Name with Charles Hawtrey (and, in a small role, the boy actor Noël Coward).

[6] During the 1911–12 Christmas season she appeared as Mrs Carey at the Savoy Theatre in Hawtrey's production of a new "fairy play" for children, Where the Rainbow Ends, with a largely juvenile cast that included Coward, Philip Tonge and Esmé Wynne.

[8] At the Shaftesbury Theatre in April 1924, Bilbrook appeared in her final stage role, Mrs Cattestock, in A Perfect Fit, a comedy by Arthur Wimperis and Harry M.

[2] Her American film roles included Lady Copewell in Dr Jekyll and Mr Hyde (1941), Lady Epping in five of the popular RKO "Mexican Spitfire" comedies with Leon Errol (1940–43), Susan in the Sherlock Holmes mystery The Spider Woman (1943), Millie in Passport to Destiny (1944), Mrs Manby in The Brighton Strangler (1945) and Mrs Vane in The Picture of Dorian Gray (1945).