I'd be straight forward with her. I would just find her when she has her guard down, and say something like "I see that you follow me around sometimes. But I never get to speak to you. You don't have to be shy, I don't mind. So what's up?".
But this is assuming you are single and actually don't mind.
Put down the mirror, you'll be fine.
Enjoy it while you got it.
All, the awkward teen years. Just ask her what's up talk to her. You know she is trying to talk to you. But is shy.
Talk to her.
Well if she never lets you talk to her then let her know that your going to have to get a restraining order on her.
(nothing says true love like a restraining order... ;p )
Haha, you got that right.