First Dad, Now Mom - Alcoholism Spreads In My FamilyRecently my mom has been drinking a lot. She only drinks beer, but in one evening she may drink up to 4-5 liters of it, and the alcohol volume is usually 4-5%. The drinking usually takes place on Friday and Saturday evenings, as she has strong work ethics. Her boyfriend drinks with her, but he drinks smaller amounts and not as fast as her. I know the amounts she drinks are too much, as I can see how she changes during the evening (I don't drink or can't drink). Fortunately she doesn't become violent like my dad when he still lived with us, but I still can't stand being around her when she's drunk, so I go home (I live a short walk away).
She didn't drink as much when my dad still lived with us three years ago. My dad was an abusive (not in a sexual kind of way) and violent drunk, and before my parents split up, his drinking had become daily, he had lost at least three jobs because of it, and the only thing he ever did between work and sleep was drinking while watching movies/TV. However, as mom was the only one he ever hurt while drunk and she never pressed charges, no consequences resulted from his moments of drunken rage. When he left for another woman, my mom had a short breakdown - me and my adult siblings were there to help her during that fateful summer break and afterwards, but she never accepted outside help and said she was fine when fall came and schools started. She worked harder than before and was promoted and got a raise in salary. She even started hanging out with her colleagues and neighbors after work and on weekends - a thing she had never done before - and seemingly enjoyed it (at least she sounded very cheerful when telling about them).
Then she met a friend of her colleague with whom she started going out. Soon she forgot her colleagues and neighbors and exclusively spent her time with him, usually doing couple things she enjoyed doing with my dad. Then somehow heavy drinking became part of that couple time. Now she has a weekend routine - after daily chores are done and everyone has enjoyed lunch, she starts drinking with her boyfriend while watching a movie, playing board games or XBox Kinect games with me or watching TV. I can always escape by going home, but my sister is still underage and can't always go to one of her friends' home, and has started showing the same shut-in response as me back when I was still living at home - lock the door and crank up the volume of TV/game console/speaker. I feel responsible as her elder sibling to help, but how can I do that? Mom thinks her drinking is reasonable, and I can't drive her out of her home to drink elsewhere. She never harms anyone physically when drunk either, so police is out of question (though she may become mean sometimes, being drunk in your own house isn't a crime). And even if an authority could do something, I don't want to risk my sister being taken away from her, because there's a high chance that she would end up in a foster family - my brother lives in a student dorm, I've been diagnosed severely depressed and my sister lives far away with her boyfriend (my dad still has alcohol problems and financial issues, so he can't take her either). Our few relatives live far away as well, and we hardly keep in contact with them (usually my mom's the one who keeps in contact with other relatives).