Question about family problems.. looking for a Biblical standpoint please?

Not quite ready to call you Abraham, but the point I wanted to make was that God called Abraham out from his family and then later, His son married his brothers daughter I believe. You need to seperate from her dysfunction by moving or disconnecting yourself from her as much as possible. Be edified by being around sound christians (doctrinally). Get away from her, get around people with sense, and be healthy. Then you will see clearly how to approach her and you will have the strength. About your sister, YOU call social services and get that girl some experienced Christian counselors because there is a spiritual component of what she goes through. Not talking devils and demons inspiring her here, but tree worship and hocus pocus puts children in a very confusing place where they see (and they do see) God in nature and yet they must deal with being indoctrinated with some mother earth garble. And whatever you do...keep your peace of mind. Have serenity...if you cant tackle it today, take steps to tackle it 3 week from then - less you stumble and have the wrong person keeping you down....Or help you up.