Elle s'appelait Sarah

Sarah's Key (French: Elle s'appelait Sarah) is a 2010 French drama film directed and co-written by Gilles Paquet-Brenner. The film is an adaptation of the 2006 novel with the same title by Tatiana de Rosnay.
The film alternates between a young girl Sarah (Mélusine Mayance) in 1942 and journalist Julia (Kristin Scott Thomas) in 2009 who is researching Sarah's story. It tells the story of Sarah's experiences during and after the Vel' d'Hiv Roundup of Jews in German-occupied Paris in 1942 and the participation of bureaucracy in Vichy France and French citizens hiding and protecting Sarah from the French authorities.
Wikipedia

This is the story of the Rafle du Vélodrome d'Hiver or the episode known as "Vel' d'Hiv Police Roundup / Raid". The most hidden historic event and the cause of the shame of a whole country, France. And it is the story of the 13.152 french jew citizens arrested and deported to Auschwitz for total extermination.
The story is about two women. One little girl named Sarah Starzynski and a grown girl called Julia Jarmond. The little girl living in 1942 and the other one in our times. The first one surviving the death of their family and the other one fighting with the ignorance of the french husband.
Two women living in two different times. Two stories.
And an amazing movie with a splendid photography directed by Gilles Paquet-Brenner.

Trailer:
https://www.youtube.com/watch?v=C8iIH8gBXEA

About the historic event: https://en.wikipedia.org/wiki/Vel%27_d%27Hiv_Roundup