Dr. David Stuart (1753–c.1814) had, late in 1783, married John Parke Custis’s widow, Eleanor Calvert Custis. Stuart was the son of Rev. William Stuart of St. Paul’s Parish, then located in Stafford County (HARDY description begins Stella Pickett Hardy. Colonial Families of the Southern States of America: A History and Genealogy of Colonial Families who Settled in the Colonies Prior to the Revolution. 2d ed. Baltimore, 1958. description ends , 493). Stuart attended the College of William and Mary and graduated from the University of Edinburgh in 1777. He practiced medicine in Alexandria, and was at this time living four miles above the city. Elizabeth Parke (Betsy) Custis (1776–1832) and Martha Parke (Patsy) Custis (1777–1854), the two eldest children of John Parke Custis, lived with their mother and stepfather. The two youngest children lived at Mount Vernon. Stuart was a member of the Virginia Assembly 1785–88 and of the Virginia ratifying convention of 1788 and was one of the first three commissioners appointed by GW for the District of Columbia. About 1792 he moved his family to his Hope Park farm and, in later life, to Ossian Hall, both in Fairfax County. In the 1780s Stuart served as translator for the many French letters that GW received, and during the presidency, he helped to keep GW informed of public sentiments in Virginia.

Sarah (Sally) Blackburn was the daughter of Col. Thomas and Christian Scott Blackburn of Rippon Lodge.