Leah grew up in Praga, a suburb of Warsaw, Poland. She was active in the Ha-Shomer ha-Tsa'ir Zionist youth movement. Germany invaded Poland in September 1939. Jews were forced to live in the Warsaw ghetto, which the Germans sealed off in November 1940. In the ghetto, Leah lived with a group of Ha-Shomer ha-Tsa'ir members. In September 1941, she and other members of the youth group escaped from the ghetto to a Ha-Shomer ha-Tsa'ir farm in Zarki, near Czestochowa, Poland. In May 1942, Leah became a courier for the underground, using false Polish papers and traveling between the Krakow ghetto and the nearby Plaszow camp. As conditions worsened, she escaped to Tarnow, but soon decided to return to Krakow. Leah also posed as a non-Jewish Pole in Czestochowa and Warsaw, and was a courier for the Jewish National Committee and the Jewish Fighting Organization (ZOB). She fought with a Jewish unit in the Armia Ludowa (People's Army) during the Warsaw Polish uprising in 1944. Leah was liberated by Soviet forces. After the war she helped people emigrate from Poland, then moved to Israel herself before settling in the United States.
So we decided to run and we ran to a ghetto in Tarnow, which just had an, an Aktion. And we came over there. And I will never forget the sight over there. It was, you know, like after a real pogrom, you know. Households, the doors open, broken glass, uh, pillowcases ripped up and, you know, the feathers in the air. Uh, domestic utensils spread all over the place. People in hiding, those who succeeded not to be rounded up. And they were not even hostile towards us. They were indifferent. You know, it was, an inhumane situation already existed there, you know, that the relations between people were not already normal. They were not human relations anymore.