Daughter of William Mackenzie (d. 1740), 5th Earl of Seaforth, and Mary Kennet (d. 1739), dau of Nicholas Kennet of Coxhow. Married (1744) to John Gordon, 8th Viscount Kenmure. She lived in France from her fourth to her eighteenth year, due to her father's role in the Jacobite Rising in 1719.
Boswell met her on September 16, 1762 at Kenmure. He admired her and her husband greatly, and thoroughly enjoyed his 2-night stay in their house.