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.
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.