The Mother Instinct.

When her baby daughter Eleanor is traumatized after her father perishes in a storm at sea, Mother Coutierre sends the girl to live with her aunt in Paris. Years later, Eleanor, now a successful model in Paris, is surprised by a visit from her elder sister Marie, who has come to hide the birth of her illegitimate child. When Mother Coutierre arrives and believes Eleanor to be the infant's mother, Eleanor continues the deception so that her sister can marry Pierre Bondel, a fisherman.