Work place romances can get you into a lot of trouble. You and her could stay madly in love for the rest of your lifes and never get in trouble. Or you could A. get fired or B. end up breaking up with her and then you work with your ex girlfriend. I am not trying to put a rain cloud over your feelings for her. It just happens to too many people.
As for finding out how she feels, like everyone has said, get to know her better and she should make it clear if she is single or not. Good Luck
