My mom stopped talking to my grandfather at some point when we were very young. She tried to do it to make him hit bottom, or something. It didn't work, and he kept drinking, and she kept getting angry about it.
Especially right now, I finally realize how angry she is about it.
She was wrong-she should have done it for her, not him. She should have done it because she made a decision to NOT have him in her life (or ours) while he was drinking, not because she wanted to force him into rehab. Because guess what? At the end of the day, not having us around (and we weren't around all that often to begin with) was more of an excuse to drink.
My mother is not the alcoholic-her bottom is not his bottom. Does that make sense?
Don't say anything to your mother. If it will cause an argument that you would rather not have, then don't do it. Let her do whatever she is going to do, and you can be uninvolved in her decisions. Keep looking out for you, and if she decides she wants your help, she knows where you're at.