Revealing mistakes: Whenever Jenna is dealing with the stove or oven, it is always off. Be it placing the pies in, taking them out, or melting the chocolate in the sauce pan.
Continuity: When Oki comes into the diner to give Dawn the flowers they are in the corner of the booth and then in front of him in the next shot, and he clearly did not move them.
Continuity: When the Exhausted Mother gets sprayed with silly string, the silly string changes color. As the mother and son are walking up to the porch, the silly string is blue. When the son sprays her during the first close up of her face, the silly string is pink. When the camera switches to Jenna then comes back to the mother, the silly string is blue again.
Factual errors: During the movie, Jenna makes two lattice-top pies by laying all of the dough strips in one direction and then placing the dough strips for the other direction on top of the previous strips. Usually lattice-top pies are made with the dough strips for both directions woven together with each other. (That way they look better and bake more evenly.)
Factual errors: When Jenna is in labor, the hospital labor and delivery room nurse is wearing a white uniform and white cap. Hospital nurses in labor and delivery stopped wearing those uniforms in favor of scrubs by the time this film was set.
Errors made by characters (possibly deliberate errors by the filmmakers): When Joe orders his lunch, he distinctly asks for two glasses of water with no ice to be brought to the table before the orange juice and the meal. However, when Jenna brings two glasses of water, one orange juice, pie and tomato, Joe complains about the ice, and the fact that Jenna did not bring salt and pepper to the table - but does not criticize the fact that Jenna brought the whole order together, rather than separately as he had instructed.
Continuity: During the wedding procession, Jenna appears NOT to be wearing her "pregnancy bump". later when she is dancing with Joe, it is all too obvious.