should i ask her out via facebook??only way...?

[~ ≡]

Guy I'm in a similiar situation with the girl I like (and just asked a question in regards to it but don't have her added on facebook)
but reading your question I remember a few awkward situations in high school where I thought about doing like this - telling them how I felt over facebook. But I never did I was to shy (and I guess still am). I don't mean to be a hypocrite but I hope I can nudge you on.
You don't need to apologize to her for anything if you do and can tell her then by all means!
Sometimes that's all I'm looking for: Take my word, I'm nudging you on. Go ahead.