Mary was the daughter of Christopher Copley but her mother is unknown. The date and place of her birth have not been found.
She had two marriages/partners. Her first husband was Ralph Bosvile. They were married, but the date and place have not been found. They had no known children.
Her second husband was Fulke Greville, who she married on 15 MAY 1602. The place has not been found. Their six known children were Fulke (c1604-1605), Dorothy (c1605-1650/51), Robert (1607-1642/43), William (c1609-?), Edward (c1613/14-?) and Fulke (c1614-1616).