I know how hard it is for you to understand what your sister has chosen to do with her life and how hard it is for you to accept that. It's a shame that we can't control those that behave in a manner that is self destructive. Fighting with her about it isn't going to change a thing so just care for your sister and feel sad that she is so self destructive. There isn't a thing you can do but stir up ill feelings, no matter who is right. She's going to do what she's going to do. Isn't it such a shame? The rest of you have your own choices to make. I'd start with, "NO", lol.