She is a coworker, not at the same department and we don't have any direct contact at work, I just met her several times and we talked very little, then I added her on Facebook trying to get to know her more, I talked to her online and she replied, then she went offline after a less than minute chatting session.

I am sure she is clever and she knows that I am interested in her, what is the best to do now, to close the chatting session (which is still not close) politely and telling her that I just wanted to ask about her and to make sure that everything is going on well at her side and not to talk to her anymore and that is it, or what to do?

Please advice.