Aimed at the children's market , "l'aventure des Marguerite " borrows a lot from other works , such as "pleasant ville" and countless others ; it suffers accordingly.
That said, can it appeal to a young audience? Perhaps so,but only partially : the part taking place during the occupation is ,in spite of numerous implausibilities, by far the best .
The modern Marguerite hints at "la grande vadrouille" and the occupied France is as accurate and as plausible as Gérard Oury's world. The exodus , when the French were running away from the German armies took place two years before (and not in 1942);Hemingway was not in France at the time ,he fought in Spain and came back at the end of WW2.
But if you forget history ,this half is pleasant enough: it's like a fairytale ,after all , as the trick of the trunk shows :so why wouldn't Marguerite help Ernest Hemingway work on "the old man and the sea"? As the resistant fighters networks were top secret , talking about them in a loud voice in a café is comic indeed. The escape from the detention camp takes the biscuit : dad is discouraged , waiting,waiting , but girlie comes to cheer him up ,and voilà! A plane pursued
by an officer whose shots are in vain (an escape which recalls "la grande vadrouille")
On the other hand, the part in modern times is ponderous and even crude (the burps competition) : with the bland long-haired boy ,who seems himself an anachronism (he looks like a seventies kid), it's really derivative (the girl whose father has left home and is replaced by a surly stepdad ) .Only the meeting with the old lady (played by Genevieve Casile ,essentially a stage actress who performed all the classics) ,a trick used often before (Ellen Burstyn in "interstellar",Teresa Wright in "somewhere in time" ) , makes up for the paucity of this half-screenplay.
Half a pleasant movie ,you make it on the percentages ,but lose out on the bonuses : but on a rainy day,it's always useful.