Why is this girl who i started to like so confusing lol.........?

There is this girl who i think had a crush on me. Flirted with hair, kept walking past me a lot, looked at me right in the eyes from far constantly. She was nervous when i talked to her alone but wasn't nervous when people around. For some reason she never initiated a talk with me ever, but she does with others openly. But I didn't really notice her or like her then. So eventually me, mr.slow started liking her... So I really didn't talk to her at all and kind of ignored her. So a month later now she tries to avoid me. but whenever she see's me she looks away immediately like she didn't notice me but I know she did. Confusing as hell i don't get it... HELP GIRLs