It's the beginning of the WWII. South of France. Patricia, 18, is the oldest daughter of a well-digger, Pascal, who considers her a princess because of her moral qualities. She's kind, devoted. One day, she briefly meets a young man, Jacques, the son of Mazel, owner of the shop where her father buy his material. He's handsome and teasing. Her father's friend, Felipe, would love to marry her, and he invites her to an aviation show. She accepts his invitation only because she knows Jacques is a pilot and will be there. Soon, she'll carry his child, and he'll be gone, and the family will have to deal with this out-of-wedlock pregnancy...

"Fanny" is the second part of the "Marseille trilogy", made by Marcel Pagnol with the generic name of "Marius, Fanny and César". Fanny falls in love and is abandoned by Marius. Now she discovers she is pregnant. Her mother and Marius's father, César, persuade her to accept the romantic advances of a much older man. To save face, Fanny accepts to marry Honoré Panisse, a rich merchant of the Vieux Port, 30 years her senior who will recognize her son.