Their children were Captain Samuel Brady, born 1756, James Brady, born 1758, William Brady, born 1760 and died in infancy, John Brady, born March 18, 1761, Mary Brady (Gray), born April 22, 1764, William Penn Brady, born August 16, 1766, General Hugh Brady, twin, born July 27, 1768, Jane Brady, twin, born July 27, 1768, Robert Quigley Brady, born September 12, 1770, Agnes Brady, born February 14, 1773 and died November 24, 1773, Hannah Brady (Gray), born December 3, 1774, Joseph Brady, born in August 1777 and died in infancy and Liberty Brady (Dewart), born August 9, 1778.
Samuel's Scotch Irish maternal grandfather, James Quigley, was born in about 1710 and came to America from Ireland in 1730. He settled on of frontier land, in what is today, Hopewell township, Cumberland County, Pennsylvania, close to present day Shippensburg, Pennsylvania. He built his wilderness home of logs close to the banks of Conodoguinet Creek. A bridge later built there caused the location of the Quigley homestead on Conodoguinet Creek to be later called "Quigley's Bridge", where generations of Quigleys continued to live long thereafter. Little is known of James' wife, Jeanette, except that she was likely of Scottish descent. However, according to local historian and author Belle Swope, "We are assured she was a devoted wife, a loving mother, and a wise counselor, or she would not have given to the world such brave and illustrious children." In 1738 the log Middle Spring Presbyterian Church was erected three miles (5 km) from their homestead, of which James and Jeanette Quigley became faithful members and in which they along with some of their children came to be buried in its old graveyard. James Quigley had to be and was ever vigilant to keep hostile Indians from killing his family and burning his home – a fate that befell many of his neighbors in those early days on the Pennsylvania frontier.
In addition to successfully keeping his home and family safe, on March 25, 1756 James Quigley was commissioned ensign in the Cumberland County Colonial Rangers.
He served as a private in the Revolutionary War. He died in 1782. They had six children, who were all born on their Hopewell Township homestead, namely, John Quigley, born in August 1731, Samuel Quigley, born in June 1733, Mary Quigley (Samuel Brady's mother), born August 16, 1735, Agnes Quigley, born in March 1737 or 1738, Martha Quigley, born in July 1741 and Robert Quigley, born in 1744, who married Mary Jacob. Robert Quigley eventually ended up living on the Quigley Homestead, at Quigley Bridge, Hopewell Township, Cumberland County, Pennsylvania. Robert Quigley and his sister Mary Quigley Brady remained very close throughout their lives.
As to the Brady grandparents of Captain Samuel Brady, author Belle Swope states, "No family of pioneers was more conspicuous in the early history and settlement of the country than the Bradys." Hugh Brady was born about 1709 in Ireland. His wife Hannah's maiden name was McCormick. One family tradition stated "the Bradys, McCunes, Sharps, McConnels, Youngs, and two other families came from County Derry Londonderry... in one vessel and landed at Cape Henlopen, " but whether Hugh and Hannah actually met and married in Ireland or in America is not certainly known.