Dorothea Muir-Mackenzie Hambourg was the daughter of Sir Kenneth Muir-Mackenzie, 1st baron Muir-Mackenzie [d. 1930], and his wife, Amy Graham [d. 1900], one of the daughters of the collector William Graham. Dorothea married Mark Hambourg (a Russian pianist and composer who lived 30 May 1879-26 August 1960) in 1907, and after her father's death inherited some of the paintings that had originally gone to her mother.