Usually this is probably because you did something to make her hate you, or someone said bad things about you in front of her. It is recommended that you find a separate opportunity to explain clearly in person and ask what is going on. Maybe there is a misunderstanding, just make it clear. But if she treats you like this, she probably doesn't consider you a friend. If you care about her, try to save her. If you don't care or you have better friends, just ignore her.