Elizabeth Washington Lewis was an American Colonist. She was the younger sister of George Washington and the only sister that survived childhood. Her half-sister, Jane, died at age 11 and her sister Mildred in infancy. Betty Washington was born into the Washington Family as the first daughter of Augustine Washington and Mary Ball Washington.

The Washington family is an American family of English origins that was part of both the British landed gentry and the American gentry. It was prominent in colonial America and rose to great economic and political eminence especially in the Colony of Virginia as part of the planter class, owning several highly valued plantations, mostly making their money in tobacco farming. Members of the family include the first president of the United States, George Washington (1732–1799), and his nephew, Bushrod Washington (1762–1829), who served as Associate Justice of the Supreme Court of the United States.