Also, if she is mentally unstable--she needs you to be strong and to be an authority for both of you , at least initially.
Think of this analogy:
A knight cannot be a knight if he can't protect his boundaries because a knight, by definition, is some rich dude that owns land/territory and fights to protect it. And if she is emotionally weak right now, she needs someone strong--not someone that gets tossed around by the waves of her instability (which she herself hasn't been able to weather).
So if you wanna help her, you essentially need to be more self-loving.
