Fantômette
Fantomette is a character in the French "Bibliothèque Rose" series from Hachette Editions, created in 1961 by Georges Chaulet. Fantomette's alter ego, Françoise, is a girl of about twelve years who dresses up in order to fight crime. She has two sidekicks: Ficelle, a tall and not-very-bright blonde; and Boulotte, a short and chubby brunette who is fixated on food. Neither of them are aware of her secret identity, despite meeting Fantomette regularly.
Fantomette was the first female superhero in French literature. The Fantomette books were aimed at eight- to twelve-year-old girls. There are 49 books in the series, which is still published today, as well as a comic book series by François Craenhals, a cartoon and a 1993 live-action TV series starring Katia Sourzac.