Hi Steppingup
"I want to tell her that I will not engage with her, argue with her or sleep with her when she's drinking. Nor will I buy alcohol for her. I love her but can't control her drinking and will take care of myself"
Well done you, you are heading in the right direction, this is a big step that took me ages to get to.
From experience, be aware of how manipulative A can be, they will beg, steal, borrow, lie to get what they want. Emotional blackmail is top of their list im afraid. In time you will be able to identify what is called here "Quacking" and as it sounds that is exactly what it is.
Protect your children in anyway you can, is there somewhere you can go when she is at her worst? This will affect them I agree with Laurie read up on how it can affect them and what you can do.
Glad you found SR, it was a lifeline for me, ive been free of my AB now for a few years, i am happy and most importantly my children are happy.
God bless
Mair