Les Malheurs de Sophie is loosely based on the Comtesse de Ségur's first two books in a trilogy: the book in the title (1859) and Les petites filles modèles (1866). Three feature films and one television film had previously been made of it, it's something which many French people remember from childhood, although Honoré gives a more modern twist to it.
This isn't the same twist he made Madame de La Fayette's La Princesse de Clèves as La Belle Personne, which of course was in modern dress and intended as a reply to Sarkozy's crass remarks on the lack of relevance to the present day of the book though: it's set in the period when it was written, although it contains more of a modern outlook towards children, and the music is in tune with the times, particularly in the final song.
And far from being a children's film, this suits all ages. Eight-year-old Sophie lives with her parents in a castle in France with relatives from the Fleurville family, her mother being Madame de Réan (Golshifteh Farahani) although we don't see her father. Sophie (Caroline Grant), in spite of her elaborate clothing, is something of a tomboy, or at least someone who likes to experiment with things, play jokes and take things apart: for instance when her father sends her a doll she pushes its eyes into its skull, then melts off its feet in boiling water; she gives her cousins undrinkable water as tea with chalk as sugar; steals the goldfish and cuts them up to 'feed' to her doll; etc.
She tries to 'corrupt' her more straitlaced cousins into mischief with mixed results, such as catching a squirrel and bringing it back to the château: for practical purposes, another trick that brings animals into the present time is that this is in fact a cartoon squirrel, and later they'll be cartoon hedgehogs and a cartoon frog.
It's on a trip to America that her mother dies, her father hastily remarries in order not to have a motherless child, but then he too dies and she returns to England not to her original château but to the home of Madame Fichini (Muriel Robin), who is a sadistic tyrant who believes in whipping children who don't toe the line. Luckily her enlightened Fleurville relatives contrive to take Sophie in while the monster is in Italy, which is much to everyone's agreement, especially as this is where Sophie gets to stay.