crysionkia,
Welcome to SR. This is such a tough problem.
You are so right that she needs to do this herself. She needs to realize she has a problem, seek help, and work a program of recovery. You cannot do this for her, no matter how sad her situation seems. Has she even admitted she has a drinking problem? Does she want help?
Speaking as an adult child of alcoholics, if her children are truly being mistreated or neglected, you need to contact child protective services. They are pawns in this little drama and have no choice in the matter. You acting as someone else's children's rescue-ranger is not a good situation for you at all, and only draws you further into a situation that you cannot control and cannot cure.
Al-Anon meetings helped me to get the tools I needed to detach from the alcoholics in my life with love. If you have a meeting near you, you may find an amazing amount of support and wisdom there, from other people who care about an alcoholic and are trying to do the right thing.
Hugs,
GL