the truth as I know it
that looks like me and my sister, with babies 3 weeks apart, or my mother and her sister, with babies 5 hours apart. oh the chumleys! my favorite crazy-ass pronunciation.
In real life, a sister more often alternately teases and ignores you growing up, steals your boyfriend, then wants nothing to do with you unless it's wedding related, and makes sure you're in an ugly dress.
I don't have a sister either, but this is what I imagine too :)
I welcome any comment, so happy to hear from you.