Since you know she works at a bank, you can find out the branch hours. Then, get there when she’s either going into work or leaving work to strike up some small talk. This way you can find out if she walks, drives or takes public transportation to work, and use that information to get to know her better. If she stops for coffee before work, you can go to the same coffee shop she frequents and try to talk to her there, too.
If you get some positive feedback, like a little conversation, a smile, and a sense that she’s interested or attracted to you, then invite her to have a drink after work.
Let me know how it goes — and good luck! 🙂