L'Ange Gardien (1942)

A former colonial official lives far from Paris with a dry cousin who pays attention to his heritage. He never took care of his son, married to a singer, even less of his granddaughter Colette. The chances of life mean that the grandfather is obliged to take in Colette for a while. This works wonders, unmasks the cousin conniving with cronies, unravels the intrigues, thwarts the machinations and reconciles all the members of the family.