In the last scene with Maddie and London, Maddie stands and puts on her bag, but as they are leaving, Maddie's bag is still on the bleachers.
In the first game of volleyball Maddie has her hair in 2 pigtail buns, but when the camera goes to a close up of London and then a background shot with Maddie in the background her hair is in 2 long straight pigtails which is the hairstyle she has in the second game. In the next shot Maddie's hair is back to the 2 buns.
In the last game of volleyball, Maddie and London's team hits the volleyball four times and in real volleyball you can only hit it three times.