Girls: I need your advice on an introverted girl?

[Johnny]

Perhaps you should know she's stared at me several times (she doesn't seem attached to anyone, really) and we already talked once (I approached her), but we don't share any classes (we go to the same Uni).
I wanna say something like:
"Hey, (sad face) we can only talk if we bump into each other", which I think would make her feel nice (would it?), but I don't know how to finish it... you know, asking her where I can find her on Facebook or something like that?
It's that she looks so introverted and shy I don't want to be pushy (for example, asking her out I think would freak her out right now).
Little help here?
Thanks! (Oh, yes, I am so clueless)

[bethany]

Whoaa slow down! I wouldn't start it like that! I would just simply say- hey!xx
If she replies then build up the small talk and get a little deeper slowly.....
Someone i see very rarely at school and have only talked to about once messages me every day and tells me almost everything! Yet when we see each other we act like we don't know each other...