I think you're making too much effort for her (pretending to go offline etc). Remember, girls are attracted to confidence. Just force yourself to walk up to her and start a conversation, even if its only quick, just show her you got kahoonaz. From what you say she likes you so you've got a window(and if you play it properly it'll go well) but if you don't act soon, your chance will pass and you're fucked. Good luck buddy