Ds and dd are 2 yrs and 3 months apart and I think that's perfect. Dd understood enough about the baby, was tt, sleeping still in the day and could get wipes etc. I can see they're going to be close because they adore each other already (poor ds wants to be running around already though).

My older sister and I are 18 mths apart which was ace and we're super close. My little sister was three years after me, then five years and then my brother. My poor brother was pretty left out of games and we all left home when he was still at school, but now we're all close.

I think personality has more to do with it than gap or gender tbh.