Hi djar, I get the feeling that even if your AW continues with recovery you will go through with the divorce process. Are you afraid that you will cause her to relapse if you have the papers served now? Or people will think you're hard hearted?
I think that's going to happen whether you do it now, or in the New Year. If she continues with recovery, you will always risk 'causing' a relapse, but any setback could do that.
For what it's worth it might be better to go ahead while she has intensive support. As you're in contact with her you could make it clear that the divorce is not an indication that you don't wish her well. Just a few thoughts; only you can choose. Whatever way you go my best wishes are with you.