Ada Prospero was born in Turin on July 23, 1902. Her father, Giacomo Prospero, was the child of immigrants from Switzerland who came to Turin at the end of the nineteenth century. The family of her mother, Olimpia Biacchi, originally from Bihac, Bosnia, left for Turin around the same time as the Prospero family. Giacomo Prospero and Olimpia Biacchi had a store that sold some of the finest fruits and vegetables in the city of Turin, said to have supplied the Queen Mother. The photograph in figure 2 of Ada and her parents was taken when she was around ten years old.

Olimpia Biacchi kept a diary of the early life of their only child, from the day when Ada was born until she reached the age of ten. She began the diary with the following words: “Here is your mother's purpose! To give you a little tiny book where all her joys and small displeasures are noted, in short, a little summary diary of your first years, up to the day when you, grandicella, can continue the work begun by your mother, who thought she was doing something you would appreciate, my beautiful, adorable angel (July 23, 1902).” She expressed her wishes for her daughter: “May your life always be beautiful and happy,” and “may your soul always be serene and faithful to the sacred obligations of honesty and duty, because only in doing our duties can we be at peace, if not really happy. From the beginning of the diary, Ada's mother alludes to the ever-present Catholicism that governs her actions and that she intends to govern the choices made by her daughter. She also implies that one cannot be truly happy in this life, casting a somewhat dark shadow over her wishes that her daughter find happiness. Moreover, by recording Ada's every action on a daily basis, Olimpia Biacchi suggests her intention to exert complete control over her daughter and creates the “psychological, social, and physical dependence” that Bonnie G. Smith describes in her discussion of a notebook kept by one of her “ladies of the leisure class” in France. The diary also evidences Biacchi's nearly absolute power over the domestic life of her family.