Betty was born in Paris in 1927 to Daniel and Ariadna Lazarus (her mother was the daughter of the famous Russian composer Alexander Nikolayevich Scriabin). Her older sister was Miriam, and she had two half-brothers from her mother’s other marriages, Eli Magen and Yossi Knout. When the Germans occupied France during World War II, they were active in the underground in Toulouse, in Armée Juive.

Ariadna was captured and executed in 1944, at age 38. Betty was sixteen and active in the Zionist underground; some of those she commanded were older than her. She fought the Germans, and shortly after Ariadna’s death, Vichy France fell. She then became a war correspondent for the French wartime newspaper Combat, crossing the Rhine with the Allies. However, her jeep hit a mine and she was severely injured. She then wrote a popular book about her experience, La Ronde de Mouche.

After the war, she met some Lehi people and was persuaded to join the fight against the British. As a Frenchwoman, she had no great love for the British, and her connections helped the underground immeasurably. She met Soviet Foreign Minister Molotov in Paris; he was a cousin of her mother. She asked him for Soviet support for a Jewish State.

Together with Yaakov Eliav, she helped prepare explosive devices and send them to various British government offices. In March 1947, Jacques Martinsky, a Lehi member, was sent to commit acts of terror against the British War Office in London. The mail bomb exploded and caused much damage. In April, Betty hid a bomb in the Colonial Office in London. She wore a coat with explosive material inside it, inveigled her way into the Colonial Office, hung up the coat and walked out innocently. The explosive did not go off for some reason, and it was discovered. The British learned to their chagrin that the underground could penetrate any one of their institutions. Betty was caught at the Belgian border with a suitcase stuffed with mail bombs, and she was sentenced to a year in prison.

In summer 1948, she arrived in Israel as a correspondent. After the Bernadotte assassination, she was arrested, but she was soon released and went abroad. She returned with her life partner Leon Hellman, and they settled in Beersheba. They had three children: Arian, Yarden and Eva. Leon dealt in heavy mechanical equipment, but his business failed. He then bought a ramshackle Arab house and turned into a successful nightclub called “Last Chance.”

Betty died suddenly of a heart attack on May 7,1965. She was thirty-eight — the exact age her mother had been when she died.