Mireille performed poorly in elementary school because of dyslexia, requiring an extra year to graduate. She was born left-handed, and her teachers used a ruler to strike her hand each time she was caught writing with it. She became right-handed, although her left hand remains quite animated while singing. She has a fantastic memory, and never uses a prompter on stage. Abandoning higher education, at age 14 (1961), and after moving to Croix des Oiseaux, she began work in a local factory in Montfavet (a suburb southeast of town) where she helped with the family income and paid for her singing lessons. Popular at work, she often sang songs at lunch, or while working. Like her parents, she is a short woman at 1.52 m (5 feet) in height. Her sister Monique (), born on 8 July 1947, began work at the same factory a few months later. Both were given bicycles on credit to commute with, making for very long days, and many bad memories of riding against the mistral winds. The factory went out of business, so Mireille and two sisters (Monique, and Christiane) became youth counselors at a summer camp before her rise to fame, a summer where she had her fortune told by Tarot cards by an old Gypsy woman, saying she would soon mingle with Kings and Queens.