I have one, and online (and offline too, occasionally) I refer to her as Sibling. We get on most of the time. Hang out in the middle of the night catching up. Who did what and when and why. Stealing each others clothes, hating on each other when we spend too much time in close quarters, but missing each other when we spend too much time away. I've hung out with
on a million different occasions, and she with mine. I read her essays, and she downloads my shows. I borrow her shoes, she borrows my jackets. She'll make me toast, I'll buy her soda. Pick her up so we can go to dinner. We try on each others clothes, and gossip and steal food off each others plates.
*shrug*. We're sisters. It's what we are.