Sarah Greenaway Miall (née Leith, 18 December 1918 – 6 October 2010), was a British rally driver and novelist, and a Second World War codebreaker at Bletchley Park.

She was born Sarah Greenaway Leith on 18 December 1918 at New Hall, Romford, Essex, the daughter of (George Easlemont) Gordon Leith (1885–1965), a South African architect who had served as a captain in the Royal Field Artillery (and was recovering from a Western Front gas attack at the time of her birth), and his wife, Ethel Mary Leith, née Cox (1888–1974).^[1]

Most of Sally's childhood took place in Johannesburg.^[1] In 1934, together with her mother and two sisters, she went back to England, and was educated at Roedean School near Brighton, followed by a bachelor's degree in English from Newnham College, Cambridge.^[1]

During the Second World War, she worked as a codebreaker at Bletchley Park.^[1][2]

In 1956, Sally won the ladies' cup in the Acropolis Rally in Athens, Greece, driving a Fiat 600.^[2] She worked as secretary to the British School in Athens, and served a committee of academic archaeologists from the London office in Gordon Square, which involved yearly trips to various archaeological digs in Greece run by the school.^[2]

As Sally Bicknell, she published several novels, including The Midwinter Violins (1973), The Summer of the Warehouse (1979), and Follow that Uncle! (1980).^[1]

• The Midwinter Violins (1973)
• The Summer of the Warehouse (1979)
• Follow that Uncle! (1980)

On 26 July 1940, Sally Leith married a fellow Cambridge student, Nigel Bicknell (1918–1990), then a pilot in the Volunteer Reserve.^[1]

They had four sons together, Stephen Bicknell (1957-2007) the organ builder and writer about the organ, and Marcus, Alexander and Julian.^[1][2]

They divorced in 1975, and later that year, she married the BBC broadcaster and administrator Leonard Miall (1914-2005).^[1][2]

After her second husband died in 2005, she continued to live at Maryfield Cottage in Taplow until shortly before her death from colon cancer on 6 October 2010 at Austenwood Nursing Home in Gerrards Cross.^[1]