It was a big part of my decision to have #2. I am an only child and DP might as well be as his sister is much older than him. When DP and I are no longer here it would mean that DD1 would be effectively alone with no family at all and that made me really sad. She would have 1 cousin who is 25 years older than her and a complete waste of space (he hasn't even met DD2, his other cousin).

So I guess one of our resons was to provide both DDs with some sort of family connections when we are gone. We can't control if they will get along but we have provided the opportunity.