I can't understand this girl?

as being a girl myself from the way she is acting its obvious she likes you. she has probably been waiting for you to make the first move. like start talking to her first instead of her. she could also be shy. another thought is the boyfriend part. if she is showing interest into you for a relationship way she may be looking for a way out of her current relationship. however i don't advise you to talk about relationships right away. get to know her first, hang out with her and see what she is like. if you like her enough for a relationship and she is comfortable enough about it i think you should go for it once you get to that part in your friendship with her. Good Luck :D