Continuity mistake: When Jill puts the piece of paper with the code for the security system on top of the system in another scene it's gone, and when she returns it's back again.
Continuity mistake: When the Mandrakises were about to leave for dinner, Dr Mandrakis opens the door then goes back to activate the alarm system behind the door. In between shots, the door goes from open to closed magically.
Continuity mistake: When Jill first arrives at the house, Mrs. Mandrakis shows Jill the emergency contact numbers on the refrigerator. Rosa's last name is spelled "Rimmerrez" in this scene. Later in the movie when Jill goes back to the kitchen to get the number from the same list, Rosa's last name is now spelled Ramirez. (00:14:00 - 00:46:45)
Continuity mistake: At the school lockers, Jill is seen ripping off a sticker from the back of her phone in close up. In the next shot, she is seen ripping it off again.
Continuity mistake: At the end of the movie, when Jill is in the hospital and the balloon pops, there are only two balloons: the one that popped and a mylar balloon. In the next shot there are about five mylar balloons. A few shots later there are only three mylar balloons, and at the very end there are five again.