I am always in that bookstore on Saturday, and she often works then. I am going to try to avoid saying anything, and just see how she reacts when she sees me. As Strat said, if she lost the address she will surely say so then.
No, there isn't anything that is sure. When you see her, she will be busy at work, thinking about work related things (unless she is a slacker). It is entirely possible that your email address will slip her mind at the moment you see her. Do not read too much into what someone fails to do. She does not know you well, so even if you're the greatest guy in the world, you may not always be in the front of her mind.
I recommend being friendly without being pushy. Try to be relaxed, and if you're a great guy, just try to be yourself.
And remember, she is at work. This affects how she will behave, unless she is a fool who does not know what she is doing. So, if you really like her, remember to not be pushy at all. Obnoxious jerks are often very pushy, and you don't want her to mistake you for one, right?
If I meet someone else I want to date between now and then, I will not hold back (this is unlikely as I am mainly at work during the week, and I think that asking someone at work would invite trouble.)
You seem like you have some sense. I may have to start looking for your audio related posts to see what you have said about other things...
I think you are right to be careful about office romance. It can work out okay, but it can also lead to all sorts of problems. I would not rule it out completely, as your (if you will pardon the expression) "soul mate" could be there, but I would not recommend looking at work as a primary meeting place. Anyway, you have no commitment with the woman at the bookstore, so, of course, you are free to keep your eyes open at all times.
And don't get too attached to someone you don't know too well, as she may not be what you imagine her to be. Be slow, and take your time getting to know her. That Aesop's fable about the tortoise and the hare is applicable to many things, and is so commonly remembered and remarked upon that it has become trite because it has much truth in it.
One more bit of advice: Whenever looking for advice on the internet like this, always think carefully about whatever is being said, regardless of who says it. Think about it all for a while (a day or two at the least) before deciding which, if any, of the advice you will actually use.