No, I don't think you are ignoring her drinking, I know you know she is an alcoholic.
However, you are excusing her behaviour in a way, she doesn't remember what she is doing in blackout, true, but she knows if she goes out and drinks too much she may black out and end up who knows where and she does it, over and over. That is a choice on her part.
As for the lawyer, I suggested that as an information seeking mission only at this point. It empowers you to have all the information, instead of thinking - what if she just runs off with our child! What will her immigration status be. You will know what the facts are and what your rights are and what hers are and you can deal within those facts, fear will have you frozen in place.
Now, you don't have to run and do that tomorrow, but maybe make an appointment for next week, some might even offer a free first consultation.
Have you discussed her getting help for potential depression (as Aries mentioned)? Or for her drinking, what does she have to say about that?