Well if you don't talk to her at all then I'd recommend putting forth effort to have conversations with her (try to make it look casual, don't look desperate lol) then after you can see that there is a "spark" then ask her out; just going up to a girl you don't talk to isn't the best way to get a date/girlfriend. You need to show her for who you are, whether that's good or bad, and if she likes and accepts you for you, ask her out. Just remember: It's better to be rejected for who you are then to be accepted for what you're not.
I <3 Breloom
"Never tell me the sky is the limit when there are footprints on the moon."