On her mother's side she has a further half-sister, Valerie Gardner, and had a half-brother, Rawdon Perry, now deceased.
[3] Her father's ancestors include King Henry VII, the first Duke of Argyll, and Lord Bute, an 18th-century British prime minister.
[citation needed] A half-plate photograph of Buchan at the age of one month, with her mother, is in the National Portrait Gallery, London.
[4] After her divorce, Buchan's mother married secondly Richard Parry (1916–1989), a Harvard-educated naval officer then working in London for the U.S. Maritime Commission,[5] and later moved with her daughter to the United States.
They settled at Chestnut Hill, Philadelphia, where Nesta Parry had two further children, and at the time of her death was still living there.