What do you do when you are, in reality, their father, but legally nothing? I raised my "step" daughter from 3 to 15, poorly because of my codependancy and my wife's alcoholism.
I did the whole "here I come to save the day" thing, and pretty much deconstructed myself in the process. I, too, was faced with the decision to leave but not wanting to abandon my then 11 year old daughter.
I did leave. It killed me. My wife allowed visitation and I did that a lot. Her ex-husband, not rich and not evil thank God, was however absent and not a factor at all. As for the girls, much damage is already done. You and your wife have been doing it for as long as she has been drinking and you have been enabling and controlling.
Leaving was the best thing I ever did. For myself, for my wife, and for my daughter. It turns out all they need from me is my company. They don't need me doing things for them (it just makes things worse), they don't need my advice, and they don't need my rules for how everything is to be done (apparantly there is more than one way to do many things and sometimes those ways work just fine, even when they aren't my way).
When I made my wife live her life on her own by truly leaving her alone, miraculous things happened. The same thing is starting to happen with our daughter. All I provided during the two years we were apart was her car and her phone. No gas, no rent, no child support, no spending money. Nothing. When daughter needed things I took her and bought or paid for them myself (did not keep receipts so it couldn't be returned for cash). Alcoholics will do anything to get money to drink, including selling their children's stuff.
Many alcoholics never find recovery. My wife did, is currently sober, and we are together. But I live knowing that each day of sobriety could be the last. Al-Anon is what makes life possible for me today. I encourage you to go.
Take care,
Cyranoak
P.s. My daughter was very angry at me for leaving. I told her why, told her I loved her, and told her that if we didn't see each other it would only be because her mother didn't allow it (manipulative but effective), and I did not worry if she would understand. I was confident that in the future she would understand. The future is here at 15, and that confidence turned out to be well-founded. She gets it. Now she's pissed that she didn't get to leave too.
Originally Posted by
Rancher 
My wife is an alcoholic. I'm ready to leave her but I'm troubled by one important issue.
Her ex husband is also an abusive alcoholic. My own understanding of my wife's alcoholism was clouded because I spent years helping to protect her and my two stepdaughter from him. The court system largely protects them now, but it came at great cost, both money and time.
Now that I know my wife's own alcohol problems, I'm ready to leave her. Her problem has systematically cost me almost everything - work, friends, and family.
My only pause is my stepdaughters. In the absence of their birth father, I have become the only father they know. However, legally I have little to no standing to have any custody rights.
I have to leave, but I want to protect them as best I can both physically and emotionally. I don't want them to think I've abandoned them.
I've been such an enabler for my wife that the girls align with her. I've worked hard not to expose them to ugliness. I can't do it any more.
I also worry that my leaving will lead to their father trying to disrupt their lives through court battles. He's very litigious and very wealthy.
Is there any way to let two young girls know that I love like they are my own even though it will seem to them that I have abandoned them?