The first thing that Margaret said to Duncan the night we brought him home was "Hi!" She said it brightly and with a cute little hand wave. I loved it, and it says a lot about how she's taking the new arrival, which is about as well as can reasonably be expected.
I have been trying not to make any monumental blunders that would make Margaret resent her little brother in any way that can be avoided. I was not carrying Duncan when I came home from the hospital, and for the first few minutes of being home I focused entirely on Margaret. This wasn't hard. I'd missed my little girl those two days I was in the hospital and having time to hug her and tell her 'd missed her and hang out a bit were important to me. It was only after that, when her curiosity was drawn to the contents of the infant car seat that we made the introductions, and I think it went well.
Margaret seems to be reasonably interested in Duncan. Mind you, I'm not clear that she actually thinks of him as a person. I think for her he's something between a doll and a pet. In my opinion this is a fine place to start. Duncan is still in the developmental stage where he mostly eats, sleeps and poops, with occasional awake periods where he waves his hands about and looks around him. When he's a bit more interactive Margaret will no doubt realize that he is more that a wiggly bundle that sometimes makes noise. Right now she occasionally asks to have him in her lap, or for me to place him in his bouncy seat or the swing. I comply with these requests unless I have a good reason not to, and that seems to make her happier about the idea of having him around. For his part Duncan seems to take his sister's attentions in stride. I supervise heavily to make sure that Duncan doesn't get hurt by Margaret since she is still a little unclear on the concept of gentleness.
My hope is that by following Margaret's lead as much as I can on the relationship she'll quickly come to see the addition of Duncan to the family as the positive thing that it is. Of course I have to make sure that Duncan finds the interactions positive too, but he's too young yet to be able to express much opinion one way or the other in the interactions. Mostly my rule right now is I won't let Margaret dictate what to do with him if he's actively nursing or unhappy. We'll need more ground rules as he gets older, but for now I think the best thing to do for the sibling relationship is to let them interact when they're happy to do so and to otherwise not force it.
All is not roses and giggles of course. There are times when I'm nursing Duncan and Margaret wants to be in my lap. Of course she can't be and that makes her unhappy. It's a perfectly reasonable reaction that just can't be helped. I do try to talk to Margaret and continue to pay attention to her when I nurse Duncan in her presence, but there are times when a girl just wants Mommy snuggles, and there's just not much I can do about it. Luckily those times aren't frequent, but it bugs me when I have to nurse Duncan and Margaret also needs a snuggle. I do explain to Margaret what is going on, and I think she's starting to understand. It doesn't mean she isn't unhappy when my lap is not available to her when she wants it, but the reality is that having a sibling does mean having to share your parents. In the long run learning to deal with that will be good for her, and eventually I think she'll appreciate having a sibling. I think Margaret's reactions are perfectly normal and understandable, so on one level it doesn't bother me, it's just that in my gut feel I have to make it better whenever my kids cry. Luckily the cuteness factor out-weighs the angst by orders of magnitude.
I feel like I had other stuff I wanted to say, but my brain is suffering from not sleeping more than three hours at any one stretch, so I've no clue what it was. I will say that snuggling with Margaret in one arm and Duncan in the other is the best thing ever.