This makes my heart hurt, Moodmuse. Truthfully, it makes me not like your sister, even though I don't know her. As I said before I could be an addict of some sort, but I would never consider hurting my children in any way, so weakness is not an option.
I guess it is a touchy subject for me because I grew up in a family of alcoholics and spent much of my life disappointed or confused. Accolades to you for taking care of her children!
Bluemountains