What should i do with the girl i like?

well, i actually like this girl, i have known her since we were young, like about 5-6? we are from the same church, but i am very shy and seldom communicate with her. every time when we are having lessons, i could see her staring straight at me and once, she even started a conversation with me, that actually gave me some false hope... because she seems super close with one of the guys and she even ignored one of my email i sent her.. i just wonder what to do? and does she hates me or something? i cant stop thinking why did she ignore my mail. her relationship status in fb is "it's complicated"