She studied at the Levinsky Teachers Seminary, and earned a master's degree in Jewish Studies, Philosophy, Literature and Bible at the Hebrew University of Jerusalem.
In 1942 she joined the Irgun, and moved to Lehi the following year. A radio announcer for the group, she was arrested by the British authorities in 1946. She was imprisoned in Bethlehem, but escaped from jail in 1947.
She was also editor of the Lehi newspaper Youth Front. After Israeli independence in 1948, she contributed to Sulam, a monthly magazine published by former Lehi leader Israel Eldad. Cohen married a former Lehi comrade, Emanuel Hanegbi.
From 1961 to 1973, she wrote for the Israeli newspaper Maariv and served on its editorial board. While working as a journalist, she came to New York to visit the Lubavitcher Rebbe, Rabbi Menachem Mendel Schneerson. Schneerson encouraged her to get involved with Israeli youth.
She was re-elected in 1977. Dissatisfied with Begin signing the Camp David Treaty and in particular the return of Sinai to Egypt as a land-for-peace deal, in 1979 Cohen and Moshe Shamir left Likud to found a new right-wing party Banai, later renamed Tehiya-Bnai, and then settling on Tehiya. Cohen retained her seat in the 1981 elections and despite their previous differences, Tehiya joined Begin's coalition.
She retained her seat elections in 1984 and 1988, and in June 1990, following a coalition crisis, was appointed to the cabinet as Deputy Minister of Science and Technology. Cohen remains active in right-wing politics. Criticism of territorial concessions
Cohen opposes all territorial concession.
She was a vocal critic of the Camp David Accords in 1978 and of disengagement plan from Gaza in 2005.
In 1972 Cohen joined Menachem Begin's Herut party, then part of the Gahal alliance, and was elected to the Knesset the following year, by which time Gahal had become Likud.
The new party was strongly affiliated with the extra-parliamentary movement of Gush Emunim, and included prominent members of Israeli settlements in the West Bank and Gaza such as Hanan Porat and Elyakim Haetzni.