She married Thomas Law, the youngest son of the late bishop of Carlisle, England, and an experienced administrator with the East India Company.

Eliza Law became a social leader in the District of Columbia, and she worked to preserve the Washington family heritage.

[2] In 1783, their widowed mother, Eleanor Calvert Custis, married Dr. David Stuart (1753–1814), an Alexandria, physician and business associate of George Washington.

When Eleanor Calvert Custis Stuart went to stay with her mother on her father’s death in 1788, the two sisters remained with Martha Washington.

[7] Law had come to Washington, D.C. after working for years in the East India Company, and used his fortune to invest in real estate in the new capital.

[13] George and Martha Washington were unable to attend the Laws' wedding, but invited the couple to honeymoon in Philadelphia at the President's House.

[15] The First Lady promised one of the slaves in the presidential household, Oney Judge, as a wedding gift to the couple, but the young woman fled after learning of the plan.

After Martha Washington died in 1802, she inherited about 35 dower slaves from her grandfather Daniel Parke Custis's estate.

[8] Following her separation from Thomas, Elizabeth resided between 1805 and 1809 at a "small country house" and estate on Seminary Hill in Alexandria, which she called Mount Washington.

[19] Mount Washington later was acquired by the Episcopal High School and used as its central administration building; it was known as Hoxton House.

[22] Law made a marriage settlement with his wife at the time of their separation, providing for an annuity from certain real estate property.

The case was finally settled in 1854 by a US Supreme Court decision (Adams v. Law),[13] by which time his remaining property was said to have greatly increased in value.