At about 3 minutes and 7 seconds into the movie as the camera pans out in Grace's (Liz Fenning) classroom, there's a world map poster on the wall which is upside down.
When Tara is facing Sophie in the rest room and Sophie says "everyone knows that picture is a fake." Tara says "some of my best work if I don't say so myself." Makes no sense. The saying is "even if I DO say so myself." No one who understands English would make that mistake.