Throughout the whole movie, pay attention to Violet's hair. In one scene, it will be a few inches below her shoulders, and another, it will be almost to her waist. And this happens every couple of scenes! It might just be me, but I didn't think hair grew that fast!!
It's the same thing with Lil's hair. She even mentions it on the DVD, they would film a scene when the hair was shorter, then wait a few months to film the next scene, but they didn't think it would make that big a difference.