Who is her “best friend”?

She again vaguely talks about her best friend will be going to Moonstone Beach with her and her mom this weekend. She’s used the term best friend for Kory, for Teeny, for her babysitter…it’s a meaningless term. I thought Kory was her best friend in the whole world but well he moved away so he’s lost his best friend status. The term is just used to mean whoever will tolerate her. She never paid Teeny any attention in recent years but now suddenly she’s the best friend I assume. If I were Kory I’d be hurt to see how easily she uses that term for anyone