Juliette Schloss was the daughter of Adolphe and Lucie Schloss and the sister of Jacques, Henry, Lucien, Raymond and Marguerite. She married Dr. Paul Emile Weil.

Juliette Schloss played a role in the transfer of the collection to Laguenne for safekeeping in August 1939. She also pressed French officials after 1945 about the status of missing paintings and their recovery.