I havent read through all the replies closely so i apologize if this is a repeat or already addressed.
I guess i'm wondering why, if you are super involved with your dd now, the process of having a baby would make her feel left out of everything? Wouldnt you include her as much as possible, as you apparently do right now? I could totally see a child of 4 or 5 being very interested in the pregnancy, the midwives visits, even the birth...caring for an infant, picking out toys/clothes/etc. You could look at it like "oh no, now she won't have 100 percent of my attention every second of the day!" or you could look at it like "wow a new chapter, and she could be so helpful and involved"...obviously there WILL be times where she wants you to play, but you are nursing or otherwise attending to the baby. I'm not sure why that seems to be the end of the world for you though. Thats life, thats natural. Its not going to hurt her.
I have four kids, ages 15, nearly 10, and two who will be 4 in a minute. I ALWAYS wanted close in age kids, but it didnt work out that way. My son was 11.5 when my first adopted son joined the family at three weeks of age. Then my second son joined the family (via foster care) when he was 16.5 months (and my adopted son was just two weeks old, so like instant twins)....my fourth child joined the family nearly two years ago, when she was 8. I really wish i would have had a closer-in-age sib for my first son, i think he would have had so much fun. But now its like he is an only child with a bunch of younger sibs he doesnt know very well (and its complicated by the fact that he's chosen to live in another state with his other parent.) When i see the relationship with the two little boys, they are so close and have such a ball most of the time (and other times they do try to kill each other it seems)...even my dd at age 9 can play well with the little boys, but adding her as an older child to the family was by far (BY FAR) the hardest adjustment. But she has alot of emotional issues as well. If you do decide to adopt in the future, make sure you really learn everything you can about the child you'd be adopting, as it can work out wonderfully or be the thing that turns your family upside down.
I totally agree with the PP who said the reason why people say you should have another if you want another, because no one can predict the outcome. Its confusing to me why that would be considered somehow an anti-child sentiment or somehow not at all considering the current child's needs.
Eeah. Totally blew my post way out of proportion and you're making rash judgements. It's not the "end of the world," as you so dramatically put it, but it is a concern to me, that she will have to divide our time, resources, attention, and that she's old enough to remember how her life was before we pumped out another unit. I don't know why it's so hard to understand concern over a total upheaval in your child's life. Actually, from what you say, I wonder why you don't seem to be concerned at all, since you've already had one child choose to leave your home and who seems to not be entirely thrilled with his pack of younger siblings.
She's the here and now and that's more important than some hypothetical future child. When/if we have another, putting her needs above the real and present second child, won't be an option any more.
I would never want to have a second child right away just in order to not have DD be the center of life and "give her a sibling". That's... I'm not even going to go there. Statistically, only children do as well or better than their peers, so I'm not worried about her not having to share her parents for her younger years if that is indeed what we choose to do.