Mary Doddridge (7 May 1733-1799) (she was generally known as Polly) lived with her mother and her two younger sisters and brother in Northampton and then in Tewkesbury after her marriage in 1759 to John Humphreys. He was a prominent lawyer in that city and was a relation of the Hankins of Tewkesbury, who were also relations of Mary's mother, Mercy Doddridge. Her husband's business failed in the early 1780s, resulting in his death, which then led to Mary Doddridge Humphreys returning to live once again with her mother. Not long thereafter Mercy Doddridge suffered the death of her son, Philip, in 1785, leaving her once again with her three daughters and grandchildren. Mary Humphreys died in 1799 at Tewkesbury and was buried in the ground attached to the Presbyterian Chapel there, the same place her sister, Celia, would also be buried. Mary's three children included one son, John (1760-1813), who studied at Warrington Academy under Drs. Aikin and Enfield; another son, the Rev. Philip Humphreys, who was educated at Oxford and became Rector of Portland, Jamaica; and Harriet Mercy Humphreys, the wife of the Rev. Robert Knight, vicar of Tewkesbury, whose son, John Doddridge Humphreys, was the compiler and editor of The Diary and Correspondence of Philip Doddridge (1829-31).