I too am sorry...perhaps this event will help you to see how damaging it is for children to be raised around addicts, your sister is a product of her enviornment and she may well have inherited the gene that predisposed her to addiction. Children, raised as you and she were, as adults have many, many issues...although we don't all become addicts, we can suffer from depression, imaturity, impulsivity, anger and a good 50% of us either marry or have relationships with "A's", not once but many times. You have children, think about this.
Vent away, remember the three "C's", keep your meetings up, if you need us, post.