When Lawrence died the estate passed to his infant heir, Sarah, the one surviving child of four that had been born to Lawrence and his wife, Ann Fairfax. Under Lawrence's will, Ann received a life interest in Mount Vernon and the use of one-half of the property's slaves; the rest of his estate was left to Sarah. The will stipulated further that if Sarah died before her mother Mount Vernon would pass to George Washington. If Sarah died childless, part of the estate would descend to her mother and part would be divided between Augustine and George Washington.
As it turned out, Sarah died in 1754 at age 4, childless, of course, and thereafter, considerable confusion arose regarding the distribution of the slaves. Ann remarried to George Lee (1714-61) of Mount Pleasant in the Nomini Creek neighborhood of Westmoreland County, the deputy clerk, justice, and burgess of Westmoreland, and a first cousin of Arthur and Richard Henry Lee. George Lee and Ann rented the Mount Vernon tract and 18 slaves to George Washington for her lifetime, at the rate of 15,000 pounds of tobacco, or £93 15s Virginia currency a year. The agreement was made in December 1754.
Let's shift gears a little here and turn to George Washington's relationships with the Lee Family as a whole. First, his associations with family members were more extensive than with any other group of persons, except for the Washingtons themselves. More than 5 dozen members of the Lee Family of Virginia appear in Washington's Papers. (See Appendix.) That is about half the number of Washingtons who appear, but by far greater than any other group of people with whom Washington ever associated. The list of Lees that came into Washington's sphere include, of course, the more famous Revolutionary War Lees—Henry “Light-Horse Harry” Lee, Jr., brothers Francis Lightfoot Lee, Arthur, William and Richard Henry Lee—as well as their siblings, children, parents, uncles, aunts, and cousins."
Lee Family Archive
http://gwpapers.virginia.edu/documents/lease-of-mount-vernon
