Agnès is most well-known for her young heroine Mimi Cracra, who has appeared in over 100 books and pamphlets and has inspired a French television series. Rosenstiehl's books have been translated into eight languages, including Japanese and Chinese. Agnès conceived Mimi Cracra's English language début, Silly Lilly and the Four Seasons, especially for the TOON Books collection. Silly Lilly in What Will I Be Today? is that title's eagerly-awaited follow-up.
Between Agnès and her husband, they have seven children and fifteen grandchildren. They live in a country house with a garden, hidden in the center of Paris.