You likely did the right thing in telling her to think about herself.
The thing YOU have to worry about is to make sure she's not just making you her emotional crutch. If you let it happen, this will likely turn out with her complaining/confiding in you, you being "HER ROCK," and listening to endless hours of her problems with her boyfriend.
This is the job of her GIRLFRIENDS, not you. From your post, it sounds like you're kind of attracted to her. If you allow her to turn you into her "male" girlfriend, she'll NEVER see you in a sexual way. Ever. No exceptions. If you are TRULY OK with this scenario, then go ahead and listen to her boyfriend problems day in and day out. Maybe you can use her as a "buddy" to get the woman's point of view with YOUR potential girlfriends. But it will NEVER happen sexually between you two.
If you AREN'T OK with the above situation, this is what you do:
No matter how much you try to convince her to break up with him, it won't happen. WHY? Because by letting her vent her problems & frustrations on YOU, it allows her to TOLERATE still dating him.
Clearly state that you think the guy is a jackass. Basically, undermine the guy's position as the boyfriend. But only hint at it or discuss it briefly. Girls have active imaginations and she'll get the rest without you going into lengthy detail. Then MOVE OFF THE TOPIC.
Hang out very occasionally, have fun, flirt, then GET OUT OF THE PICTURE. Chicks first realize they have romantic feelings for a guy when the guy isn't around and she still finds herself thinking about him. If you hang around her constantly, this will never happen. NEVER, get into deep, emotional conversations. ESPECIALLY about other guys or girls.
The longer you hang out with a girl, the more she learns about you and the more likely it is you'll screw up and start revealing alot of your inner thoughts, fears, dreams, and aspirations. In short, you'll spend all of your "mystery" too fast.
You know what they say, "When the keg is empty, the party's over."
When you're with a girl and she's kind of into you, your goal is to ration out your mystery one little nugget at a time. That way, by the time "the keg" (mystery) is empty, she will have been you such a long time that she's in the habbit of being with you and she stays out of lack of momentum (or some such thing).