Grimas (2012) on Netflix

Sophie Meijer lives with her older brother Kevin after their parents died in an accident. When Kevin his salary is being reduced, she decides to accept a job as a babysitter with the strange couple Richard and Annette van der Werff. During her first evening, she is confronted with the horrible secret of the house. She manages to escape and is hospitalized where she meets Chantal, the previous babysitter. Meanwhile, three detectives discover that the nightmare isn't over yet and that both girls are in grave danger...