I’m the oldest of three sisters. Three is a BAD number for siblings — two always gang up on the third.
Dunno how it happened, but I ended up with a son and a daughter, in that order. Heh, that was almost as unbalanced! ;-)
But the alliances shift constantly! I'm the oldest of three sisters too, but we also have a brother. Funny, in the 60's and 70's, four kids was a small family.