In the 1930s there followed three anthologies, some journalistic reviews, and a third biography,
The Tranquil Heart (1937), about the Italian Renaissance author and poet
Giovanni Boccaccio. In 1936 came a publication dedicated to Lord Tweedsmuir (
John Buchan), written in collaboration with her husband Donald and illustrator
Evelyn Dunbar (later commissioned as one of the few female official British WW2 artists):
The Scots Week-End and Caledonian Vade-Mecum for Host, Guest and Wayfarer (George Routledge & Sons Ltd). In 1940 her husband Donald was killed in a street accident during the
blackout. She continued to live alone in London, working on a two-volume biography of John Buchan together with his widow, Lady Tweedsmuir. Volume 1,
The Clearing House, appeared in 1946 and Volume 2,
John Buchan by His Wife and Friends, in 1947. Catherine Carswell died of pleurisy after pneumonia on 18 February 1946, aged 66, at the
Radcliffe Infirmary in Oxford. Her son John edited her fragmentary autobiographical texts and published them in 1950 as
Lying Awake: An Unfinished Autobiography. ==In fiction==