 Richard Bentley, classicist and master of Trinity College, Cambridge, was her maternal grandfather, and Richard Cumberland (1732–1811), playwright, was her brother.She spent her childhood in the town of Stanwick, Northamptonshire and in Fulham, Middlesex.In 1762 her family relocated to the Kingdom of Ireland, when Denison Cumberland's father was appointed as chaplain to George Montagu-Dunk, 2nd Earl of Halifax, Lord Lieutenant of Ireland.