Elizabeth Roboz Einstein
Roboz married Hans Albert Einstein, first son of physicist Albert Einstein, and professor of hydraulic engineering at the University of California, Berkeley, in June 1959. They did not have any children together, although Hans had four children from his first marriage to Frieda Knecht, only two of whom survived into adulthood. Hans died on July 26, 1973, and Roboz wrote a biography of him, "Hans Albert Einstein: Reminiscences of his Life and our Life Together" (1992).
Elsa Einstein
Elsa Einstein (18 January 1876 – 20 December 1936) was the second wife and cousin of Albert Einstein. Their mothers were sisters, making them first cousins, and further, their fathers were first cousins, making them second cousins. Elsa had the surname of Einstein at birth, lost it when she took the name of her first husband Max Löwenthal, and regained it in 1919 when she married her cousin Albert.