Klingberg's daughter, Sylvia, became a left-wing activist in Israel and member of the socialist anti-Zionist movement Matzpen. In 1975, she married Ehud Adiv, an Israeli political activist serving a prison sentence on charges of spying for Syria, in a ceremony held in Ayalon Prison. They divorced after three years. Sylvia Klingberg later emigrated to France, where she became a Communist activist and married French philosophy professor Alain Brossat. Their son, Ian Brossat, is since 2008 a member of the Paris City Council for the French Communist Party. Sylvia died in October, 2019.