She was widowed when John Parke Custis died of disease at the end of the American Revolution at Yorktown where he served with his stepfather, George Washington.

[4] After their marriage, the couple settled at the White House plantation, a Custis estate on the Pamunkey River in New Kent County, Virginia.

[6] John died intestate, so his widow was granted a dower third, the lifetime use of one-third of the Custis estate assets, including its more than 300 slaves.

The estate was distributed as the daughters married and the son reached his majority while Calvert's share was held by her for her use until her death.

[6] Calvert died on September 28, 1811, at age 53 at Tudor Place, the home of her daughter, Martha Parke Custis Peter, in Georgetown, District of Columbia.