I'm sorry to say this, but sometimes these things can peter out; it happens. I've had the same thing happen a few times over the years. She may also just be very busy; she sounds it.

To your second to last paragraph, it does seem like she's not really busy, but instead has, for whatever reason, lost interest. It isn't necessarily a sign that you did something wrong. Sometimes it's nice to meet someone, get along well, and move on without the pressure. Remember, some people just don't have the energy to maintain too many friendships like that; I'm one of those people.

It would be best not to bug her about it, because it may scare her off, ... I'm a guy, so I dunno how that would work with women, as perhaps it's different for you guys, but if a woman bugged me because I didn't contact her, then I'd get a bit annoyed, same if a guy did it; it'd have the exact opposite reaction than the intended. I don't like to feel obliged or expected to talk to someone.

I have this AMAZING as heck friend from Denmark; we've known each other for ... not sure, actually... possibly a year. This woman never pressures me to contact her, as I don't with her. Because of the lack of pressure, we talked when we felt comfortable and ready... I swear, she's amazing. I'm glad I took the time to get to know her. But yeah, sometimes you just have to be patient and not stress about it. If it doesn't work out, there's lots of awesome people out there!

By the way, the woman from Denmark and I actually also initially talked every day for ages; it did indeed peter out a bit, but not the friendship, just the frequency that we talked. We still sometimes talk for ages on end, especially lately, as she's been struggling with her back and I wanted to cheer her up.

Best of luck!