No one on TSR will be able to tell you for sure if she likes you, the only person who can do that is the girl.
You said that you haven't made any attempts to "woo" her. So instead of doing that, you're trying to analyse her behaviour and any "signs" that she may like you.
What you should do is flirt with her, if she reciprocates then that's a good indicator, or even better asking her out for drinks or a meal. It's pointless looking at trivial things like smiling because a lot of people smile, it's just what people do to be friendly!