I have 3 children, and each time all of the siblings were at the birth. As we always do everything else together as a family, I really couldn't imagine them not being present at such an amazing, family changing event.
My daughter was 4 years old and present at #2 birth. I had a homebirth, and the midwife woke my daughter up in the middle of the night only moments before #2 was born. One of my strongest memories of the birth was pushing and seeing my daughters huge smile while seeing her baby sister born.
When I had #3 my two daughters were 6 and 10yo. I had another homebirth, and they were both present for that birth as well. I honestly couldn't imagine them not having been there, and feel that there was very strong bonding in seeing their siblings being born.
We did prepare them in advance by being present at the pre-natals with midwife, reading books and having them watch natural birth videos so they knew what to expect.
I am now pregnant with #4, and my son will be 3yo when it is born. I would like for him to be there--but I'm not sure yet if I should have somebody there with him in case he isn't interested, or is clingy to me and I want some space. I don't have anyone I would be comfortable having at the birth. My daughter was 4--and there is a huge differance in understanding between a 4yo and a 3yo. However, I have watched birth videos with him, and he is in absolute awe and such a HUGE smile when the baby is born--so I really would like him to be there. We will see.
I just wanted to share my experience's with having children at my births.