She was born Wilhelmine Margaret Eve Cresswell on 1 December 1911 at New Hunstanton, Snettisham, Norfolk, the daughter of Lieutenant (later Captain) Francis Joseph Cresswell (died 1914) of the Norfolk Regiment and his wife, Barbara (née Ffolkes or ffolkes; 1884–1977).
[2] Her father was killed in action at Mons not long after the beginning of the First World War, aged 31.
[3] From the 1930s, she lived between Norfolk and London, where she had a flat in Holborn with her sister Puffin and worked for the Georgian Group.
[3] After marrying the economist Sir Roy Harrod in 1938, she moved to Oxford, where he was an academic, and where she became friends with John Betjeman (to whom she had been briefly engaged in the early 1930s) and his wife Penelope Chetwode, amongst others.
[1][3] In 1957, Harrod and her co-writer Charles Linnel published the Shell Guide To Norfolk.