I got a great-niece in May and a niece early this morning, so Phoebe will be well-endowed with cousins on my side of the family, which is kind of nice since my kids have always existed as...their own little pack...on that side of the family.
To be fair, my family is complicated (as is evidenced by the great-niece being the same age as my niece and daughter), so I do have some great-nephews around Alexander's age and a great-niece between Benjamin and Miriam. But that's still a tricky relationship for me to navigate (as their mom was raised in an adoptive family and only got back into contact with us in more recent history, so although we count her as family it's still feels a little more distant to me somehow (it probably would help if I'd seen Amy more than twice in my life)). And technically the twins exist; they're a year older than Rachel (but they live with their father, who doesn't allow them to have much contact with our family at all). So in essence, my children have been in what we call a "cousin hole." There just haven't been any cousins for them to associate with when my family gets together.
They can never remember if Rosie is their cousin or their aunt (they usually default to referring to her as aunt) because Rosie (my niece) is a few years younger than Josie (their aunt, who is nine years younger than me). My brother is two (and a half, as he loved to point out our entire childhood) years older than me. And their oldest babies and my youngest babies will all be the same age!
So that'll be fun!