What bugs me is that she does all that and I feel like I have to talk to her but when I do, she becomes a bit difficult and gets kinda quiet and all sarcastic :/.
Most Helpful Girl
She might want to be all happy bubbly chatty with you, but then once you start to talk back she's like, "Oh good he's talking to me like he wants to! Oh no, I'm being so ditzy and fake. I have to be more like myself!" and then she acts more sarcastic, tries to guard herself again, because she wants you to take her seriously and not be interested in a fake version of herself.
Don't assume I'm right though, just thinking what reasoning I would personally have had when I was naive enough to act like that.