Firecallie-
your mom is killing herself with alcohol because she has the disease of addiction. There is nothing you can really do......being the 1st, 2nd, 3rd or whatever child has nothing to do with it. If she wants to quit she has to hit rock bottom or decide to "just" quit, if not...I would use my time taking care of myself at this point. You have done all that you can. Addiction affects everyone around the alcoholic or addict if you let it, do not let it......
Blessings,
Kahlia