Conscious or not, the "inability to understand" what the other person is saying is a killer controlling maneuver. Think about it. If you're unwilling to do X unless she understands why, then all she has to do to prevent it is not understand.
Your W may be beyond the point where she can will herself to change her drinking behavior. It may be that the best thing you can do for her is to allow her to hit bottom (i.e. allow her to get into enough pain that she breaks out of denial and sees the harmful consequences of her behavior). You can't make any of that happen, you can only let go of trying to prevent it.
At some point along the way, I learned that it is pointless to try to talk with someone who is drinking (or using, or whatever). They are under the influence and they are not "present" for any conversation, so don't waste your breath.
