WG, don't "should" on yourself. It's only natural to start having those thoughts, but you gave so much and did all that you were able to. The reality is that IF you had done the things you mentioned, it probably would have made no difference in the outcome--because of her active alcoholism. Perhaps she WAS sober for the last month or so, but the damage had already been done. Considering the circumstances, you did your best and you have no reason to second-guess yourself or feel guilty.
You are stronger than you know and you will get through this.
Hugs,
Connie