A friend of a friend. We met two years ago, havent stayed in touch, but I think I have already established comfort with her, but she now has a boyfriend. really need advice on this.

Leave her alone since she already had a bf? Unless you're telling me you wanna split them up.

Try to become better friends with her, eventually she will confide in you about her problems with her boyfriend, and when she does that you can start trying to subtly make yourself seem better in comparison (the usual boyfriend destroying routines, you can read about them elsewhere on this site).

Like a friend of mine once, I told him that I started crying next to a guy in bed, he asked how did the guy react, I said, "He didn't know..." and my friend was like, "Wow, how could he not know?? You can always tell when a girl is going to cry, before it even happens!" (In this particular case the friend really wasn't into me - he was obsessed with his ex - but you can see how he made himself seem so much better than the guy I was with, without directly insulting the guy.)