I'm of the older generation and therefore my advice might seem a little old fashion, but it's good advice you can take to th bank. First of all, working for the same employer would be my first concern. If you tell this girl what you're feeling and she finds it to be the least offensive, she may go to your boss. This in turn may or may not cost you your job. At the very least, it could make working around this girl extremely uncomfortable and put your reputation at risk. Instead of putting your heart and reputation on the line, try inviting this girl to go to a social function with you, or ask her to lunch. After spending some time with her AWAY from the work place, you should be able to get a feel as to what she is thinking. You might "drop" the names of a favorite hangout or two frequented by other lesbians in the area. If she is familiar with them, there is a good chance she may be gay, or at least gay friendly. Since she has done nothing to make you question whether or not she might be gay except to smile at you and be cordial and friendly, (as anyone in the workplace is expected to do) you don't really have much to go on. After all, I am friendly and might smile at a male co-worker, but that certainly doesn't mean I want a relationship with them. If after seeing her outside the workplace, she does not respond by inviting you out, then I would forget about her as a possible relationship. Just enjoy a purely platonic friendship as a co-worker. If, however, she does indicate she has feelings for you, my advice is to move very slowly, and not be to quick to reveal your feelings, until you are absolutely sure they will be reciprocated, GOOD LUCK!