Yvaine doesn't have friends, she has sisters. Sisters who are morally obligated to be your friend and really don't have a choice as to whether or not they want to deal with you.

And him. She has him, she supposes. Though there isn't a great deal of choice involved in that relationship either.

"You are telling me that you didn't get into the least bit of trouble when you were younger?" she quirks a curious eyebrow - Yvaine was a horrible little sister.