Born: November 22, 1722, at her maternal grandfather’s home, Hertingfordbury Park, Hertfordshire, England.
Died: October 15, 1797, at her home in Devonshire Street, Paddington, London, England.
Buried: South Audley Anglican Chapel, Grosvenor Square, Mount Street, Westminster, London, England.
Maria was the wife of Major Cowper, sister of Martin Madan and cousin to William Cowper.