[Acheron]

First: your friend's ex isn't interested in you. Any girl that tells you that any girl would be lucky to have you isn't interested in you. It's an absolutely classic sign of being in the friend zone. That isn't necessarily a bad thing: having cool friends is always nice, and she'll likely be able to introduce you to her cute friends. But if you can't deal with only being her friend (and remember, that will inevitably involve her telling you about guys she likes), just stop talking to her.

Second, that online contact sounds like it has very little potential. She has no pictures up and made first contact, which girls rarely do. That means she's obese. That pretty much applies to any girl without a picture, any girl with no full body shots, and almost any girl that sends the first message. The problem with online dating is that it's absolutely cutthroat. If you're a guy that isn't getting dates in real life, you won't get them online either except by sheer weight of numbers. Most girls you message will never reply.

A general tip for online dating, though: never have a prolonged exchange of messages with a girl on the site. In the third or fourth message, ask to meet up. The longer you leave it after that, the more risk you run of running out of momentum.