Stern was born in 1929 in the farming village of Rakosin in the Carpathian Mountains. Rakosin was then in the most easterly part of Czechoslovakia but was annexed to the Soviet Union in 1946. It is now Rakoshyno in Ukraine.
Stern’s father Lazar died when she was five. Her mother Regina was left alone to care for their three sons and five daughters. The family was extremely poor. They only owned a small plot of land, a cow and some chickens. All the girls slept in one bed.