Distancing myself from my alcoholic friend, who lives with her enabler alcoholic mother

I'm her last friend. One by one, she's offended or ostracized them...yes, she has bipolar depression, but somehow I've always been unbothered by her long stints of self-isolation, and she's let me see her vulnerabilities but never asked too much of me. For a time, I stayed because I worried she'd self-harm if she was left friendless, and she's gotten on her medication and started to level out in a way I haven't seen in a decade or more from her. I have been able to maintain my boundaries... we'll never live together again, I won't have dinner with her, and we won't go out to the clubs or lounges. We all grew out of our partying and binge-drinking...she didn't have friends to party with anymore, but she kept the drinking and the drinking and the drinking.

Her mother pays the rent and makes sure she has a roof over her head. And, together, they drink 2-3 bottles of wine every night. I dropped in on them a couple of hours after work once, and they were both already wasted before dinner, at home watching Netflix. Every night. I've seen the bottles build up outside their back door over the course of a week. When I've met her in the afternoon, she'll swing by the liquor shop on the way home; very often, her mom will call her and specifically request that she pick up bottles of wine or mixer for spirits. My friend can't manage her own money, so her mom transfers money for alcohol.

She won't acknowledge the amount she drinks, but I could call her any night of the week and she'll be slurring. Anytime I bring it up, she just says she only drinks on weekends and has no problem. Her mom will freely confess to how much they drink and then talk about quitting - and my friend will say her mom should quit, but that she herself has no problem. I've pushed the conversation multiple times and she'll just shutdown under confrontation. This is how she lost all her other friends: she couldn't handle herself with alcohol and came onto their boyfriends, abandoned us go fuck or hound for drugs on nights out, and would just shutdown if confronted on anything.

If I lived with her again, she'd behave - she's always held herself to a higher standard around me, and I know it's because she loves and respects me like no other person. But I'd end up supporting her 100% again, food and rent, because she's just not equipped to handle life by herself. If she didn't live with her mother, she'd have nowhere to live at all. She's spent everything her dad left her, when he died in his forties with a glass of whisky by his side at nine o'clock in the morning.

Anyway. She told me last week that she's been shitting blood for two months. I told her ancient grandmother, and the angel of a woman is taking her to the doctors to start all that. The woman's pushing ninety and the only sensible person in that whole family.

I hope my friend hates me for snitching on her and dumps me; I'm too soft to dump her. In my head, I've already decided it's probably cancer or something terrible...when she told me about the blood, I tried to be kind when I wanted to smack her in her face. I brought up going to the doctor and why she can't ignore symptoms like that, and she just acted like she couldn't hear me.

I love her though. I really do. She's just ended up the model of someone so intelligent that they're consumed by endless anxieties, and yet so deliberately obtuse when it comes to her own addictions. I want to punch her mother for letting her live this life... but her mother is the one putting a roof over her head, and I won't take her on as a dependent again. What am I going to do? Get an octogenarian to help stage an intervention for both of them? I just can't imagine supporting her through all the horrible things that are coming and wish I could move overseas and that she'd lose my number or find some guy who'd love her and look after her, so I wouldn't feel this burden.