Hi Will,
I'd second what Holistic Star said. In my years of being a coach, one of the biggest mistakes I've seen eager new coaches make is seeking to be understood before they understand.
People invariably shut down when they're told what to do before they feel others understand why they do what they do.
I'd suggest you keep in mind these 2 powerful PD concepts which have served me well:
1) Seek first to understand, then be understood. Only when you know where your sister is coming from can you really help her, and like Star said, the very act of feeling understood by someone helps take a load off already.
2) There is a positive intention behind every behavior, whether the behavior is positive or not. People who smoke know it's bad for them, bt they smoke anyway, maybe because they want to
relax. She may be overworking herself, for e.g., but for what? Perhaps she's looking to
achieve.
Whatever she's doing now, there are positive intentions driving her whether she's aware of them consciously or not, whether the behaviors and results are positive or not.
3) Tell stories. Using indirect methods to persuade someone can be more useful than telling them outright sometimes. Like Star said, instead of saying, 'hey, there's this subjective belief thing and I think it'd work for you', tell her a personal story of how you didn't believe it (like her), what made you change, and how it's benefited you.
Or take her out to an inspiring movie, or give her a book that talks about subjective belief systems.
I'm not knocking the direct persuasion method, but when one is the best to use is a judgment call I best leave up to you
4) Be the change you want to see in the world. I didn't say that, Gandhi did. 'Nuff said
