Normally when it comes to that, I'd just throw her response back to her with a wink "I don't give out my number either..... let's do smoke signals!" - the key is just being playful and doesn't let rejections faze you.

If a girls says, she doesn't give out her number, I'd either just stand there in silence with a deadpan stare. Trust me, they will break first and start qualify themselves. Or if I want to be playful, I can throw in some fun responses then just stare at them.

I'd never give my number to a girl unless we're exchanging numbers. Otherwise, it gives her control. Now you have to wait around for her to call you.

Its semi interest.

Its likely that she didn't want to appear "easy" either. A lot of those instant rejections are just knee jerk reactions. Men have to understand that women aren't social experts. She likely doesn't have the courage or confidence to do what you just did, so she is unsure of the proper way to respond to it. Men tend to be a lot better developed in social situations because we take a lot more social risk. I.e. approaching women. Don't assume the woman you're talking to is able to match you socially.

When you don't know what to say next in conversation, its likely that she also has no idea. She has no idea what she would do if she were in your shoes, because she lacks the courage to even be in them. They're just looking for us to guide them.

I don't think this is something to worry about now. Its over with. She contacts you and you handle it from there, she doesn't and you move on; possibly seeing her again and giving it another shot if you want.