 On 26 September 1761, she married John Campbell, Viscount Glenorchy, eldest son of John Campbell, 3rd Earl of Breadalbane and Holland, one of Scotland's wealthiest landowners.In 1765, while recovering from illness, she came under the influence of the sister of Rowland Hill (the evangelical Anglican preacher), and experienced a religious conversion.Particularly after her husband's death in 1771, she devoted herself and her wealth to furthering evangelical causes, becoming an influential figure in Scottish Church affairs.