When Kate and Zoe are walking alongside a yellow school bus on the way to Zoe's first day at school, a mother with her son is crossing the road. As the mother and son pass the front of the bus, the son drops his book. The son tells the mom and they pause in the path of Kate and Zoe briefly before being forced to move on, leaving the book behind in order not to block Kate and Zoe. A crossing officer attempts to pick it up for them before leaving it as the mother and son exit the scene.
While playing Monopoly, Kate was excited to land on Free Parking when according to official Monopoly rules, there is no reward for landing on the space; however, it is a widely accepted house rule in most circles that there is, in fact, a generous cash prize for landing on Free Parking.
When Kate starts the pillow fight with Zoe, she takes a pillow in her right hand, ready to swing it from right to left. On the next camera shot, she swings the pillow from left to right with both her hands.
Blue painter's tape on the floor in the hallways between the two rooms marking the spot where the actors stand in several scenes. Also, the rug in the hallway is there when there is no blue tape, gone when the tape is there.
The goof items below may give away important plot points.
In the final scene, Kate and Nick are cooking in the kitchen. Zoe is serving the food - and her hair is down. Food preparation guidelines for restaurants indicate that food preparers (including servers) with long hair must either have their hair fixed up above their collar (as Kate does), or pulled back in a ponytail. Zoe's hair is loose.
When Kate comes into the restaurant after her sister's death and finds Nick there, he is singing. A kitchen cloth is in Leah's left hand behind her back. In the next shot where he sings to her baby, her right hand holds her stomach with the kitchen cloth. However, in the next shot it is in her left hand again.