You are right, only she can fix it. Like yourself married for 20+ years. H just finished 28 day program after years of drinking. I can't tell you how many tears and screaming matches over the years we have had. By the grace of God he didn't get DUI. Alanon helped me when I started going earlier this year. My most valuable lesson was loving detachment. I let things take their own course and he realized after a crisis involving a trip to a hospital and a BAC where he should have died, he agreed to an in house program. If I would have called into work for him giving excuses as to why he didn't show nothing would have happened and things would have gone on the way they were. But instead NOT calling made him make his own decision. (I told him after he was in the program that if he hadn't admitted himself I would have ended our marriage and moved away with our daughter.)
Quit focusing on her and focus on you and your children. Live your lives without her. If she wants to be a part of the family let her know that she has to be sober. Don't let her drive, of course and let her know why. And then leave it at that. Walk away. No arguments.
Keep coming back to this forum too and talk to us. We listen.