Born Margaret Agnes Feilding, she was the daughter of General Hon. Sir Percy Robert Basil Feilding (1827–1904) and Lady Louisa Isabella Harriet Thynne (died 26 June 1919). She married Sir Walter Edward Davidson on 21 October 1907, and was thereafter styled as Lady Davidson. In 1918, Davidson was invested as a Dame Commander of the Order of the British Empire (DBE) in her own right, and later as a Dame of Grace, Order of St. John of Jerusalem. She was thereafter styled as Dame Margaret Davidson.