Mme Mills, une voisine si parfaite (2018)

Hélène leads a sad life as editor of cheesy romance novels. But one day, when the old and delightfully eccentric American Mrs. Mills moves into the apartment next door, there is a sudden return to her everyday life. The two unequal women make friends in a hurry and Mrs. Mills is finally even the new face for Hélènes publishing - and that brings great success. But actually the old lady pursues a completely different plan. And is she even a lady?