I agree.
I know the usual posters will pipe up with 'siblings don't always get along' etc. But the majority do. My siblings are the closest people I have in my life, aside from my husband, my son and my mother. We've been through losing our dad together. There's no one else that could ever understand that grief and walk that exact path with me. And no, this isn't the only reason we want a second child, we also just want to have another child, and we can afford to etc.
Yes, not everyone can havea second child. But these are the reasons I have tried so hard, after having 3 losses. I'm now 12 weeks pregnant with our 2nd.