Short answers, pulled from the story.
Lieserl Einstein was the first child of Albert Einstein and Mileva Maric, born on the 27th of January 1902 in Újvidék, Austria-Hungary (now Novi Sad, Serbia). Her existence was unknown to biographers until 1986. Her fate is undocumented; the most widely accepted hypothesis is that she died of scarlet fever in September 1903.
Albert and Elsa Einstein were first cousins through their mothers and second cousins through their fathers. Elsa's mother Fanny Koch was the sister of Albert's mother Pauline, and Elsa's father Rudolf Einstein was the grandson of a brother of Albert's paternal grandfather.
Hans Albert Einstein was a professor of hydraulic engineering at the University of California, Berkeley. He earned his doctorate at ETH Zurich in 1936, emigrated to the United States in 1938, and became widely recognized for his research on sediment transport.
Eduard Einstein was diagnosed with schizophrenia at the age of twenty-one and was institutionalized multiple times. He spent most of his later life at the Burghölzli psychiatric clinic in Zurich, where he died of a stroke on the 25th of October 1965 at age fifty-five. He is buried at Hönggerberg Cemetery in Zurich.
Hermann Einstein and his brother Jakob co-founded Elektrotechnische Fabrik J. Einstein & Cie, an electrical engineering company based initially in Munich. The company manufactured arc lamps and dynamos and installed lighting systems across southern Germany and parts of northern Italy before closing due to competition from AEG and Siemens.
The surname Einstein is either a German habitational name derived from the Middle High German verb meaning "to enclose or surround with stone," a Jewish Ashkenazic adaptation of that German name, or an ornamental name built on the suffix -stein, meaning stone.