Is anything ever "pretty" with an alcoholic? There are times I'd give every penny I had not to deal with my alcoholic mother ever again, and I'm betting my father is feeling the same way. You can't put a price on your sanity, my friend. She will dig her own grave and doesn't seem to be as smart as she thinks she is. Alcoholic are notorious for big bluffs and lots of threats they can't keep up with. She can find her own attorney, you don't need to assist her with that!
You gave her 17 faithful years, what has she given you in return?
Divorce is ugly, alcoholism is uglier. Peace and sanity are priceless. You owe it to yourself to move forward with your life. It's time.