Difficult situation with sister

[Truetoself]

My sister is an alcoholic and may have undiagnosed nental heal th condition such as borderline personality disorder. She separated from her husband 6 years ago and estranged from her kids. My brother and I tolerated her for years due to understanding that alcoholism was a disease and she may be mentally ill but her behaviour crossed a threshold that we can no longer tolerate. So we are also estranged from her.
The issue is my mother. She is very controlling of my mother and dictates how she lives her life. She keeps threatening to end her life. My mum is scared of this and also says we should have compassion as she is ill. My sister knows she is an alcoholic but doesn’t want to recover. We have offered her to go to rehab that we will fund several times.
Her control of my mum is having an impact on myself and my brother as my mum would also them be irrational in her requests to us. I can’t go low contact with my mother as she has a chronic illness and needs support with her appointments. My sister doesn’t drive so can’t help with this.
My brother and I feel my mum needs to establish boundaries with my sister but she is not brave enough to do this.

My question is- given my sister is an alcoholic with mental health issues, how can we show compassion whilst protecting our own mental well being?

It’s all about the boundaries, boundaries, boundaries.

Setting them and sticking to them.

I would continue to see your Mother but be clear you won’t engage with discussion around supporting your sister and set boundaries on how you can support.

That would be my steps before considering no contact.

you mention control of your mother by your sister. Financially? Practically, you and brother need to sort a power of attorney for your mum

I don’t talk to my sister for different reasons (she had severe MH issues and personality disorder) she would do things like threaten to accuse me of awful things and harm herself and once did it and my dc were aware so I never saw her again. I also realised if I never saw her she can’t falsely accuse me of anything. Like you I have a DM who is constantly worried about her and telling to restart contact etc

I agree with the pp. You and your brother can continue to support your mother but be crystal clear that you are NC with your sister and wish to remain so. If your mother cannot accept this then you may have to consider arranging carers to help with her support and medical needs. You can still keep contact with your mum but insist your sisters behaviour is not up for discussion.

Is your sister living with your Mum? Wondering how sister is having that level of influence? Agree you & your brother need to get POA for your Mum.

Thanks everyone. My mum already has a will but good point about POA. My nanny lives with my mum. My sister has fallen out with my nanny and wants my nanny to leave my mum’s home. Up until now my brother and I would collect her and bring her to ours when she wants to visit. However now we are both so busy and concluded that the next time my nanny is chucked out, she should plan to move in with myself or my brother for good (our spouses are on board with this. We could do this now, however I know loneliness is detrimental to health and we are worried about my mum being on her own as she is already unwell. My nanny is a companion and also helps around the house.
My sister would fall out with someone and expect my mum also to cut contact. Basically she dictates how my mum
should live and this is how she controls her. I think this is ridiculous and my mum is crazy for even entertaining the idea. I also get angry with my sister. But my mum says I should show compassion as she is sick.

Sorry about the drip feed . I was giving an example of how she controls my mum.

I am stumped as to how I can show compassion towards my sister.

Never mind about your sister. Decide how you want to interact with your mother and leave it at that. Don’t talk about your sister to your mother or let her raise the subject. If I were you I would disengage from your sister entirely. She isn’t going to change.

Yeah that’s what I have done but the impact on my mother impacts me. But I can be more strict about my own boundaries

Please get a DOA in place asap. This is a distrubing update. Is nanny a relative? Sorry you are having this situation

If I was trying to show compassion to an alcoholic sister (she needs to admit this btw) then point her in the direction of AA. Go with her to the first meeting. Then leave her to decide whether to engage with AA. It may work, it may not but you have tried