It may be because Peanut is so much older than the Princess, or it may just be that she is not old enough to really annoy him yet, but my children actually get along so far.
It is a beautiful thing to watch them play together every day. Peanut shares his toys with her and Princess happily plays with all of his cars and batman action figures. They play ball together, and today they played peek-a-boo for nearly 1/2 an hour. It was super sweet. I love this and I hope they stay friends forever. I know it is too much to ask, but I can dream.