Two of Us (2019) on Netflix

Plot summary

Madeleine Girard and Nina Dorn are retired women who live next door to each other on the top floor of the same building. To everyone around them, including Madeleine's daughter Anne, the two are simply neighbors. In truth the two women have been lovers for more than twenty years, and nobody else has been told. Madeleine is a widowed grandmother with two children. Nina, alone across the landing, wants a life with Madeleine in the open. The pair plan to move to Rome together, and Madeleine has promised Nina that she will tell her family the truth about their relationship.