Sarah was born on 1920, in the city of Lysychansk, Ukraine to Bella and Yerachmiel Levstein. She had two brothers, Yaacov and Herzl; both were Lehi activists. The family made aliyah in 1924 and settled in Tel Aviv. Sarah studied in elementary school and afterwards in the Herzliya Gymnasium. In 1937, the family moved to Jerusalem and stayed there two years, until returning to Tel Aviv. During this period, Sarah studied in the Hebrew Gymnasium in Rehavia. She was a member of the Beitar movement and part of the “nationalist circles.” In 1936, she joined Hagana Bet (Nationalist); after training, she began working in the armory.
In 1937, after that group split, with some choosing the “left-wing” Hagana, it became officially known as IZL, and Sarah joined it. In 1938, she was sent to a six-week commanders’ course in Kalmania. Afterwards, she became a company commander in Tel Aviv. In this role, she trained her men in weapons. In 1940, after World War II began, IZL split, and Sarah followed Avraham “Yair” Stern, joining Lehi.
On the holiday of Sukkot, a few weeks after the split, Sarah married Uzi Yellin, who was also a Lehi member and activist. Uzi was arrested in September 1940, was released and re-arrested for a short time, then arrested for a third time and sent to the Mizra Camp and afterwards to Latrun, where he spent a year-and-a-half. Throughout that period, their house was under surveillance, and the CID would often question them. This kept Sarah from any activity and any contact with her friends in the underground.
The Yellins had three children: the firstborn, David, born in 1942, died in the Yom Kippur War as a deputy battalion commander in the Armored Corps; the second, Azgad, was born in 1945; the third, a daughter, Diklah, was born in 1950.
After the State was established, Sarah worked for a time as a school secretary. The couple settled in Ariel in Samaria. Sarah was widowed in 1999..