Elderly sister who complains constantly and is paranoid. Should I just cut ties with her?

Is she willing to get help?

If she has been like this most of her life, and you mom also had similar issues I'd say it's a mental illness rather than age related decline. The symptoms point to paranoid schizophrenia. Would she see a psychiatrist to get a diagnosis and medication for treatment?

Angel

alamar, has your sister been to her primary doctor recently? If not, maybe she has an urinary tract infection which can cause the very same issues that you are writing about. Get your sister some help.

Alamar, your profile says that your sister has Alzheimers/dementia. Have you discussed her diagnosis and recent sympomts with her doctor? Have they explained how that condition can make you do all the things that she is doing? Depending on what stage she is in, she may be very paranoid, delusional, and difficult. I'd make sure that it wasn't something else, like a UTI, drug reaction, etc., but if it's her dementia, it would help if you learn a lot about the symptoms, stages, and how much this is effecting her. Some patients need medication. You could discuss that with her doctor, too. My cousin, in her early dementia became very disagreeable. It was very confusing for me, because I was nice to her. It wasn't until it progressed that we figured it out. So, I learned that dementia isn't just about memory. It may change the personality and make people difficult too.

Are you her Durable Power of Attorney? Is she still competent to sign one? Of course, you may not want to be the person to make decisions for her, but I would figure it out now, as the condition will progress and she will need increasing amounts of care and supervision. Is there anyone else to take this on?