In 1766 she inherited her ancestral estate and title of Blair Drummond from James Drummond, the infant son of her brother George, who outlived his father just over a year. Agatha Drummond's son, George Home, later changed his last name to Home-Drummond.
Shortly before his departure for London in November 1762, Boswell travelled with Lord and Lady Kames for a great part of his harvest jaunt, through the southern counties of Scotland. He stayed with them at Kames from October 16 to October 26, 1762. He described (in his journal entry of Oct 16) Lady Kames as a woman who "was very handsome and still has a very good presence. She is a woman of good understanding and very well bred. [...] She has a great fund of humour, and a peculiar turn of strong and brilliant propriety of expression. [...] [T]ake her all in all, she is an excellent woman."