Mary Chew married William Paca, signer of the Declaration of Independence, in 1761. She was the daughter of Henrietta Lloyd and Samuel Chew as well as a descendant of John Chew who came to Jamestown on the Charitie in 1622 with three servants. There is little known about Mary except that "she was the favorite granddaughter of Samuel Chew, the head of one of the oldest and most prominent Colonial families."
William was a young lawyer and member of the Maryland Assembly at time he married Mary. Mary and William were parents of five children, but only one child survived - John P. Paca (married Juliana, daughter of Richard and Mary Tighlman). Mary did not live long enough to enjoy her husband's many successes as he served as a delegate to the General Congress, Justice of the Supreme Court of Maryland, and as Governor of Maryland. She died in the first year of the Revolution.
William married Miss Anne Harrison, a highly respected young woman of Philadelphia, in 1777. William and Anne had one child. Anne and the child both died within three years of the wedding. William died in 1799 at his ancestral home, Wye Hall, Harford County.
Facts and quotes are from Wives of the Signers: The women behind the Declaration of Independence, pp. 219-220.