I am so sorry to hear about your sister's daughter. I can understand her struggling, though. The whole process IS such a struggle, but I guess if you look at the big scheme of things it's understandable. To put it in perspective, you just have to remember that many people who quit smoking have to quit 4 or 5 times before they stay off them. I am glad that your niece is beginning to see that her children are being well taken care of. It is very distressing that she is pregnant again... such a shame. Is your sister thinking of taking this baby in too? I am thinking that perhaps her daughter just isn't being put in a position where she has to face the truths of how her addiction is affecting everyone. Losing yet another child certainly doesn't seem to be smacking any reality into her head! You and your sis must feel so discouraged at times.
I wonder what would happen if a real hard line was taken? Does she have court ordered visitations? Does she see the kids at all? It is so hard when you have the kids, because you know the best thing is to cut all ties unless they are sober/straight, etc. If they have visitation that is difficult. If she continues to use, I suggest that your sister requests limited, supervised visitation with regular drug tests (if that is available there). The more that your niece must face the reality of her situation the better her chances are of at least straightening up and staying out of trouble. It has to be so difficult for the kids.
At any rate, you are correct. There isn't much else that you can do besides be there for your sister. She needs all the emotional support that she can get. She is lucky that she has you, Rose. I honestly don't know how she manages.
Warm hugs,
Didi