I'm 32 years old. I drank longer than 5 years but vodka became my primary drink and I would drink a litre or more a day. I've had two DUI's, and went to the hospital twice in the span of 3 years for pancreatitus attacks. I also lost my job and my fiancee two weeks before the wedding was supposed to happen. I left the hospital 37 days ago and that is the extent of my sobriety. I vomitted about two pints of blood when I was admitted and when I left it still took me about a week before I could walk without pain. This is only part of my story, if she continues the damage can be extensive. In my case I'm lucky to even be alive she may recieve a worse fate if she continues. I will pray for your sister and I hope she finds the strength and will to quit before things get much worse.
The damage will be a very painful death. I hope she gets some help.
Primarily the liver will be affected. In severe cases the alcoholic could develop "wet brain." I am not exactly sure what that is, but I have known someone with it. Not pleasant.
She has become addicted to alcohol. Alcohol can cause some damege to her system but you want no till problems start.