How to ask this girl out?

[Chae]

honestly bro. I would stay away from her. stay far far away form her. At least till she is completely over her relationship. it's not even about him. it's her who has to let go. until then, you will be just a tool. yes, there is a chance that she will find someone else if the timing is bad. that's just how it is.

But to answer your question b/c you probably going to ignore my advice above, given that your only source of contact is FB, you can FB msg her and ask her for her number. it's not a big deal.

Take it from someone who has been there. don't get involve in a girl who has a BF no matter how she expressed how much she want to end her relationship. I have seen girl who said she wants to break up with her BF for 2 years. It aren't going to happen. Until it happen, don't even think about it. you will only waste your time.

you might think she likes you, but if she really likes you, she will be with you by now. believe that.