STALK HER DOWN WITH THE INTERNET! lol, no don't do that. I'd say she'll call you when she's ready. Maybe she's going through something and wants to be left alone. If she doesn't reply within a couple months or more, you could try and call her again. That's what I'd do.
If you know where she lives then you could call around to her house, check in on her and see how she is. Otherwise, I'm afraid you'll just need to leave her have her privacy. Though I can see why you'd be worried, it's a little strange.