Siri von Reis was the daughter of Bror Gustav von Reis (1903–1975), the president of Detroit Broach and Machine Company of Rochester, Michigan, and Donna Tavastila von Reis (1908–1994).[6] She received a bachelor's degree in botany from the University of Michigan in 1953.[6] After breaking off an engagement to the electronics executive Arthur G. B. Metcalf in 1959,[6] she married the Jewish American banker Arthur Goodhart Altschul, a Goldman Sachs Group partner and member of the Lehman banking family.[7] They had three children together, Arthur Jr. (born 1964), Emily Helen (born 1966), and broadcast journalist Serena Altschul (born 1970), before their divorce in 1972.[7]