C,
My kids always knew dad had a disease. So when wacky stuff happens we blamed the disease. Not sure that was the right thing to do. I never hid it, as they have their dads DNA and I wanted them to understand addiction. ( biggest blessings in my life, that so far my kids are not addicts)
Not sure if they are old enough to hit an alateen meeting. That might be an option.
They can see mom but I would get a third party. If mom is under the influence I would tell the person to tell the kids mom is sick today and have them leave her home. Tell them she needs to be well before they can spend time together. Mom needs to understand that she can't be drunk around the kids. This is setting up boundaries. Protect them at all costs, that's what being a good dad is all about!!
Hugs my friend, keep posting and venting.