Thomas Martin Einstein
Albert Einstein had three children, Lieserl Maric (1902–1903?), Hans Albert Einstein (1904–1973), and Eduard "Tete" Einstein (1910–1965), but only Hans Albert is known to have married and had children. Hans Albert's only biological child to survive to adulthood was Bernard Caesar Einstein (1930–2008), who was a physicist and the father of Thomas Martin Einstein.
Helen Dukas
Her name was actually "Helene" and she was the daughter of a German-Jewish merchant named Leopold Dukas. Born, raised and educated initially in Freiburg im Breisgau, she had six siblings and a son named David, and her mother was named Hannchen (née Liebmann). Hannchen Dukas was coincidentally from the same town, Hechingen, that Elsa Einstein, Albert Einstein's second wife, hailed from. It was through this connection that Helen Dukas would gain the position as Albert Einstein's secretary in 1928. Following Elsa Einstein's death in 1936, Dukas would take on many of the housekeeper tasks for the Einstein family, by this point living in Princeton, New Jersey, where Dukas would remain until her death.