[KarenInCa]

I can relate.
DH and I strongly considered keeping our DD an only child. I have a 24 yr old, but he was moved out on his own by the time we brought DD home, so really she would have been raised as an only child. I think they can potentially get bored as an only child, but I also think that they can get a lot of one on one attention that siblings don't get. With our current daughter being the only child in the house right now, we dote on her often, and of course she is wonderful in our eyes, and she has no competition in the household, besides the dog. But there are also times that she wants to play and we just don't want to, and I think siblings would spend time playing with each other.
However, even after we considered adopting again, we had second thoughts. As an only child, we would be able to afford private school as she grows up, and all the things that neither DH nor myself (nor my bio son) have ever been able to enjoy. We decided to adopt again, because we wanted our first daughter to be able to bond with a sister who has the same heritage. For some reason (a feeling more than anything else) that was extremely important to me.
We've asked for a child 12-24 months old, the same as we asked with our first DD-she was 16.5 months old on adoption day. If we get a child in that age range, and if it takes 3 years total from DTC to referral, then there will only be a 3 year difference between them, and our first daughter will be 5 yrs old when we travel back to China.
It was definitely a leap for us to decide though.