Hi Manmust,
I am a recovering codependent who has a workaholic husband (a legitimate addiction) and an alchoholic/addict brother. Based on experience, I believe you are describing an alchoholic, and I think you need to get away while you can. You really cannot save her, or her son (which is sad, of course). If you stay, I have no doubt you will sacrifice your health and sanity. If you stay anyway, please (and I am not being snide) go ahead and begin seeing a therapist with experience in this area.