She was the daughter of Edward Spencer of Rendlesham, Suffolk, where she was born.

[1] Thus she was the sister of Elizabeth Spencer, later the wife of Sir James Dashwood, 2nd Baronet,[2] and the aunt of the future Anne Stewart, Countess of Galloway and Elizabeth, Duchess of Manchester.

His second wife having died in 1729, the duke married Anne Spencer on 21 August 1737.

They had three children: The duke died in 1743, aged 40, and was initially succeeded by James, his 21-year-old son from his first marriage.

[9] They had three children: The duchess died in 1771 and was buried at Easton, Suffolk, under the terms of her will.