That's your problem right there, you are trying to "fix" her. You can't "fix" an alcoholic or drug addict. First of all, they have to want to get sober/clean for themselves, nobody else. If they want to get clean for other people, they will relapse very quickly. Have you spoken with her family about her alcoholism? You know, sometimes it is better to let people hit their bottoms and not "saving them" from hitting it. That is called enabling, you are allowing them to continue the behavior with no consequences. Maybe this is her bottom, you leaving her.
MOREPAIN, you sound like my father-in-law, who will do anything to keep his wife from hitting rock bottom. You are actually hurting her more than helping. You are enabling the activity/behavior and she doesn't see a problem or consequence because she doesn't have to face it because she never gets there, you "save" her. Divorce won't be her rock bottom, because she will think that YOU are the problem, not her and alcohol. You want a simple solution to this, MARCHMANT ACT her! If you truly feel she is a dnger to herself and/or her kids because of the drinking, you can have her placed in a rehab facility. Trust me, you can work through things without going to divorce. The kids need to see that you are exhausting every avenue before getting a divorce