That's a hard question to answer, I'm a layperson in this department. My opinion is that her coping systems and values may be vastly different from what we'd consider average, so I'd say that anything's possible. Mental illness automatically trumps the expectation of our being able to foresee or predict or comprehend her behavior, and it's a moot point to try to evaluate the thoughts of another-- ill or not.

The only solid, credible evidence you have to work with lies in your own experiences with her. Her actual behavior toward you must be your only indicator of the value in your relationship with her. The question then becomes whether you are willing to allow someone to treat you in this way. If her friendship means enough to you to tolerate the uncomfortable feelings, then you have to temper your own feelings to accommodate the hurts and disappointments. If you choose to disallow her brand of behavior toward you, then it's your responsibility to refuse it and avoid it.

The bigger root in all this is whether she has already attempted to release you. Additionally, if she is emotionally unstable, her priorities could easily shift with the daily winds.

I'm rambling, I know, but my basic feeling is that if someone consistently drains good feelings out of us and does nothing to replace them, all that's left is negative feelings. No one wants or needs that.