Is My Baby Bird Nesting?

I've heard about expectant moms "nesting" as their due date nears, but is it possible for expectant siblings to do the same? I think my 3-year old, in his own way, is as sick of the wait as we are and is starting to nest in his own big-brotherly way.
He has a huge imagination and is always pretending and acting anyway. But lately, a lot of his pretending centers around his sister. Currently, his stuffed monkey (Curious) is in the baby's crib. I was informed by our future Oscar winner that Curious is his sister and that she needs rest....she needs a blanket....can we turn on music for her?....I was also instructed to be quiet because she was sleeping and that I should leave the door open so we could hear her if she woke up. I also overheard him comforting "her" --- Don't worry, I'm right here....You OK.....
And when we are not upstairs, there is often an imaginary friend/sister that I have to keep up with.
I guess with all the things I've been worrying about regarding the adoption, one thing I can cross off the list is whether or not superboy will make a good big brother. :-)
However, perhaps something I should add to my list is Little Brother. Today my son informed me, rather nonchalantly, that he wants a brother and a sister. At least his demands are down from a few months ago when he told me that he wanted 5 brothers and 5 sisters. Geez. If he only knew! It took us 6 years before we were blessed with him. And it is 2 years and counting as we wait for #2. At about 4 years wait per kid, multiplied by another 9 kids.....oooh. That's not a pretty thought. So for now, we will just focus on what seems like the ever-increasing wait for our daughter from China. What the future holds after that, who knows?