Happened to me in person too. I'd say leave her alone - if she wants to come to you, she will. If you ask her if she wants to be friends, etc, she might take that as you being needy and clingy and then write even less because she doesn't want to lead you on. And then she'll feel awkward talking and writing to you because she'll think you're reading into everything she says.

It could be that she's just super busy right now. I'd give her the benefit of the doubt, and a lot of space. Let time tell you how she feels about you. In the meantime, look for another friend to chat with!