Recently I wrote this post about photographing your children on their level by squatting down. In general, I think moms should make a habit of employing that technique. However, there aren't any "rules" of composition that can't be broken. Often, doing something unusual can produce a compelling and interesting image.
One of my favorite techniques when photographing my own kids is shooting down from directly above them. It emphasizes how small they are and highlights their helplessness. One key, though is to make sure you get their attention - seeing their eyes is often what makes the image work. Check out these examples and try it for yourself.