In 1940 she and her husband were staying with their old friend Dornford Yates and his wife at their house near Pau in France when France surrendered and had to escape from the advancing Germans through Spain to Portugal.
Britton and Matheson Lang formed their own company, which toured India, South Africa and Australia from 1910-13 performing Shakespeare.
In later life she sat on the governing board of the Old Vic Theatre.
Her first appearance on stage was with Frank Benson's company in 1901, in Henry V. Among the Shakespeare parts she played were Hero in Much Ado About Nothing (1903), Ophelia in Hamlet (1909), Lady Elizabeth in Richard III (1909) and Lady Macbeth at Stratford (1911).
In 1914, she and Matheson Lang successfully produced The Taming of the Shrew, The Merchant of Venice, and Hamlet at the Old Vic Theatre. She also appeared with him in Mr Wu, which became his signature role.