Do girls like the straightforward approach from someone they don't know very well?

I've had a crush on this girl for a couple months now, we work at different times of the day so I only see her if I stay late. The only reason I can stay late is because of the influx of work around the holiday months, and with them almost done with we will return to regular schedule for the next 8 months, and I won't have a chance to talk to her anymore. She's always working, or talking with her friend, she's not very social, and mostly keeps to herself. You can see how difficult this makes it for me, a guy who works in a separate department and has no work relationship with her whatsoever, to strike up a conversation. With time running out I'm frustrated to the point where I've decided to just flat out tell her how I feel. That I think she's very pretty, and that I've had a crush on her but been too much of a sissy to do anything up until now. I won't go into greater detail as this is already a lengthy description, but I wanted people's opinions on how she'll handle a straightforward confession from a person she doesn't know that well. Should I even do it?