Read several books on body language. Then observe that person's body language when she is with you, especially for a while. Also observe her body language when she is with other people. Look at her eyes and see if her pupils dilate as she talks to you for a while in the same light. Take her for coffee in the pouring rain. You will see if being with you is worth some inconvenience to her. You will see how she reacts to the inconvenience, how angry it makes her. You don't want to get involved with someone who can't handle annoyances calmly.

I would repeatedly see her alone at nice places in the daytime. Find out if she wants to continue talking to you when there's nothing else to do, no lights, no music, no other people to ogle, no excitement. Just hanging out with you. The place should be classy and nice, as a compliment to her. But just daytime. Even mid morning coffee and cake. See if you bore each other. You might. A woman will get the idea that you just want to talk to her, if it's in the daytime. That is much better than the usual, a little excitement then go away already. Let these little coffees go on a little too long so you see if she's dying to get out of there because she has seen you long enough. If that's true, it's not there. If you linger at the table, you will learn more about her, because she will get tired and show more of her true self. If she enjoys that, she's yours. If not, you haven't spent tons of heartache. In summary, ask for SOMETHING, but not a HUGE something. That is in between doing nothing at all, and throwing yourself at her feet in a puddle of worship. Make a move but carefully so a smooth exit is available if needed and nothing big and awful happened. It's coffee, not dancing til dawn. That I do not advise. That's only for later, when all is well, to celebrate.