Well, I received the first sign of understanding (with regard to the new baby) from Aidan yesterday. I'm standing in the kitchen, and he walks in patting his belly with both hands. At first, I thought he was just being goofy, until I noticed that he was staring at my belly while he did it. Then he walks over to me, pats my belly, and says, "Baby." Yesss! I was really excited. I mean, we've been trying to explain to him for the last seven months that there's a baby in there, and for the last couple of months that his baby sister is in there, so it's exciting that he's finally gotten some kind of grasp on the concept.
Later on in the evening when we were all together, John asked him about the baby, and Aidan again patted my belly and showed Daddy where she's hanging out. He even gave her a kiss! It was too cute. Something that is funny about it, though, is that he doesn't like my belly to be uncovered. John would lift my shirt up over it, and Aidan would immediately pull it back down, like it freaks him out or something. It freaks me out sometimes too, buddy.