I'd say no you can't go for # at that place, because she could get in trouble. You gotta be considerate to ladies. But there are always exceptions, and perhaps you could and get away with it. Up to your judgement.
What you can do is flirt with her and if signs are right ask what time she finishes. If she answers the time you can be there at that time, and then you can n closer with her, WHICH I don't recommend. N close and then escalate to after work date immidiately, they get flattered when you take it just a lil too far, a date might not be too far, but then you can smell her hair, ask if she wants to kiss you, and if those go well ask if she wants to watch a funny movie at your place. They get flattered when you take just one step further, it tells them you're into them. To take her for date tell her you're going to this place and if she wants to tag along with you, so you can see if she's qualified to be with you. (don't go would you like to go out on a date with me)
When you flirt with girl, you gotta let her know you're into her. Ask her if she's single (not have bf, "Are you single?"). She say yes I'd question her response, "Are you reaalllly single???" Then hmmm, what time you finish your work?
If on your question what time she finishes she respons with anything but time, she don't want to meet you, or is not compfortable telling you at that place. Act like it don't affect you, but don't flirt with her further, take your bread and leave. You could try again next time, after you about to disconnect with her ask what time she finishes. No answer, forget it man.
Oh, accuse her of being into you as soon as she meet you after work for your n close. From that point on keep accusing her. It's flirting.