Mama (2013)

Jessica Chastain (Zero Dark Thirty) stars in her first horror film as Annabel, a punk rock bassist who unexpectedly becomes a surrogate mom to her boyfriend’s two young nieces when the girls are found after five years of having lived feral in the woods in the wake of their father’s death. How they survived remains a mystery until Annabel starts taking seriously the older girl’s stories about “Mama,” a protector figure their psychiatrist thinks the girls made up. But Mama is very real, and, without giving too much away, has taken care of the girls in an attempt to right a wrong that was done to her during life years earlier.