Simone Balfet was born in the southern French department of Tarn in 1924, the daughter of a protestant pastor and of a mother who had graduated from the Ècole normale supérieure in Sèvres.

[1] In 1946, she joined the Mouvement Jeunes Femmes (MJF), whose aim was to enable married Protestant women to put their Christian convictions into practice and to feel solidarity with each other.

[2] The aims of the MFPF were officially to promote the psychological wellbeing of couples and the health of women, but above all, although implicitly, to answer the many questions about birth control, as information on this subject remained prohibited by a law going back to 1920.

[1] The political context of the post-1968 years fueled the process of radicalization of the MFPF, and the counsellors, led by Iff, increasingly opposed the physicians on the movement's board of directors.

[6][7] From 1970 until 1973, Iff became general secretary of the Parisian section of the French Movement for Family Planning, where she helped to organize the training of counsellors, alongside that of doctors.

[4] After François Mitterrand's victory in the 1981 French presidential election, Iff became a technical advisor in the office of Yvette Roudy, Minister for Women's Affairs, whom she had known for a long time.

There, she obtained a ruling for abortions covered by publicly funded health care in 1982 and fought for enough places for voluntary terminations of pregnancy in hospitals.