Mary Hassall (nee Rouse), the eldest of Richard and Elizabeth's children, was born in England and made the sea journey to New South Wales as an infant. For a period prior to her marriage she worked for Elizabeth and Lachlan Macquarie as a governess to their son Lachlan junior. In 1819, she married Jonathon Hassall (d. 1834), the son of missionary and landowner Rowland Hassall. The marriage produced eight children, five of whom survived to adulthood. Mary was widowed in her mid thirties and never remarried.