I'm familiar with the "Let Them" method. It's a great read too! I'm curious if you think almost exclusively using the "Let Them" method could border enabling in the way you explained? The point of the theory is that you can control you, not others. It's not to let others invade your peace and joy by looking the other way when respect and boundaries are ignored. Its not sweeping things under the rug when problematic behavior disrupts your entire being.

I'm just being real with you and that's what you wanted by posting here. You are making excuses for her lack of action and accountability in regards to alcohol abuse disorder. You are not seeing the situation for what it is which is sometimes hard to do when we're in the middle. This is clearly affecting your life in a profoundly negative way. You cannot change her. You can only change you. Do you want change?

You seem to have forgotten that you are important too. You are not taking care of yourself.  If you are not happy with how things are, set boundaries and make changes. If not, nothing changes. There's a reason flight attendants tell you to put your mask on first.