I agree with lido, too. I would not message her again. It sounds like she is avoiding you because she doesn't want to deal with the potential awkwardness of having to express that she is not interested. If she felt a romantic spark, she would have messaged you back and she would have put effort into getting to know you. Her initial messages to you were very polite, but not more than that. Still, I think it's great that you took the chance of reaching out. You never know if you don't try. Hopefully the next time you take a chance on contacting a girl, it'll be the "right" girl.