You Fail to See...
That this girl is currently in a relationship.
You've put her on some kind of pedestal and cherish the ground she walks on. Don't you think you're being a little pre-mature with your anticipation and feelings when she is bound to another and even if she leaves him for you, she'll be in a rebound situation (google "rebound relationship") and educate yourself about being unfortunate enough to be caught in the situation as the role of the human bandaid.
I ask you (as I've asked so many men in this forum lately who don't seem to care about helping girls to cheat) How would you feel if you do steal her away from her current boyfriend and she turns around and because she has no personal or relationship boundaries, she allows the next guy on the assembly line at work steal her away from you?
You're just looking for trouble. Karma and all, ya know? She doesn't sound like she cares who she hurts why would she care about you. Is your ego so large that you think you can be the one that she suddenly becomes integral and monogamous for?
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion