Daughter of Hugh Hume-Campbell, 3rd Earl of Marchmont and Anne Western (d. 1747). Married (1763) to Major-General James Stuart.
Boswell met Hume at Marchmont House on October 18, 1762, describing her as "very ugly, but clever and snappish". They next saw each other when, on April 14, 1763, Boswell chatted with her at Lady Northumberland's in London, almost repeating his previous description of her, this time as "pretty clever, but snappish". He met her again on May 20, 1763, after apparently having missed an engagement with her.