Why does my best friend act like this?

My best friend is making me and my other besty feel super excluded from our group of friends. She's been behaving this way for awhile, but it got really bad last week. She does a lot of little things to make us feel bad, but they really add up! We're fed up, but what do we do? Please help! I don't want to lose my friend but I can't take this crap anymore!

Props for typing properly!

I would guess that your friend is just going through a phase and there's really nothing you can do about it. A little break does good sometimes; just let her be for a while. Tell her first that you don't like her these days and you will always welcome her back as a friend when she's ready to change, but she's the one who has to make the next move.