Does this girl like me?

Ok there is this girl Cindy at my school. we talk and text constantly. She loves calling and talking to me. She is gorgeous by the way(idk if u care to hear that or not) i tell her how pretty she is and she is really cool and fun to talk(coz she is) I'm starting to like her I think she can tell.she would talk to me even when she went out with this other guy. But she is one of my gf's friends. My gf and I are pretty much as non-compatible as you can get. we argue all the time and fight. I''m pretty sure she doesn't want to be with me anymore(never wants to talk or anything) and Cindy knows this. i would like to be with Cindy but isn't that wrong? Does Cindy actually like me? What should I do?