Hell, I have 2 brothers and a sister that were delivered at home the "old fashioned way" - at home.
I suppose there was no question as to who the father was but we - myself included - and my father were there, as well were many close family members and friends.
IMO, I think it's important for siblings to see their brothers and sisters born. It's a natural process and I'm grateful for having seen 3 live births in my life. IMO, only then you can really put life into context (not as a kid) but latter thinking about that experience..