Yonah Guy is the daughter of Miriam and Zecharia Yefet. The Yefet family was also called Hassan al-Fadel. Yonah was born in Israel in 1928. The family lived in the Beit Israel neighborhood in Jerusalem. The family sympathized with the underground activity and their home became a center for various activities of the underground. Weapons training and lectures were held there, and at night, groups would come out from their home to hang “The Ma’as” posters. Her brother, Haim Yefet “Eitan” was in Lehi, she had a sister in Etzel and another brother in the Haganah. In 1944 she joined the Lehi in Jerusalem. She served in various positions in the Youth Division, recruitment, warehouses and as a fighter in charge of a youth division. Among her commanders were Shimon Barmetz, Mathitiahu Peli, Zvi Frank, Kalman Alboim “Tsfania” and Naftali Cohen. She participated in hanging poster and leaflets and in the attack on the central prison in Jerusalem on January 19, 1946. She was arrested after Brandot’s murder, she went on trial and was released after expressing her willingness to join the army. She studied social work and Psychiatry at the University of Jerusalem.