The Giraffe's Neck (2004)

Mathilde (Louisa Pili), a precocious 10-year-old, insists that her grandfather, Paul (Claude Rich), help her find his ex-wife (Mathilde's maternal grandmother), Madeleine (Monique Melinand), who ran off years ago. With only the letters that Madeleine wrote to her daughter and granddaughter to guide them, they journey from Paris to Spain looking for her. Meanwhile, when Mathilde's mother, Helene (Sandrine Bonnaire), who's spent her whole life hating Madeleine, discovers what they're up to, she joins in on the search.