When Sarah and her dad are on the ship travelling to New York he gives her a locket with her mums picture and his picture in it. Her mum is on the left and her dad is on the right. Later on when Sarah's necklace is taken off her by Miss Minchen the pictures have swapped around and her dad is now on the left and her mum on the right. Then when the other girls steal Sarah's locket from Miss Minchen's office her mum is once again on the left. This is definitely a slip up.