Hello, Allieb, and welcome to the forum. I'm very sorry about your mom. The symptoms she has been displaying ARE those of end-stage liver disease. If you will go to the folder entitled Hepatitis Resources, at the top of the forum page, you will find a lot of info in there, including a discussion of "how much longer?" Since each patient is an individual, it is impossible to estimate how long someone has. I think some doctors try to scare patients into sobriety by telling them they only have 6 mos. to a year to live if they don't stop drinking. But it's true that they are hastening their death by continuing to drink. It's like pouring gasoline onto a fire.
Were her bleeding varices banded? Is she taking Lactulose for the elevated ammonia levels? Who is caring for her at home? She could continue like this for months, or things could go bad very quickly. If you read some of the older posts, you can get a sense of what happens--especially to those who continue to drink or who stop too late to affect the outcome.
You are not alone and I am sure you will find lots of support here from those who have been through the same thing you are.