Crush on a taken girl, but I can win her over?

Well, I like this girl who admitted to liking me before but i never knew and i liked her too. but now she has a boyfriend and I still like her, and she acts like she likes me too which is kind of confusing. Her relationship is so obviously and publicly falling apart and I feel like maybe that's a good time for me to kinda move in I guess, but would it be a bad idea? Any suggestions or help? I reallllllllllly like this girl and I feel like I could fight for her