Undiagnosed aunt declining at home after post-surgery delirium

My 80-year-old aunt has been showing signs of dementia for years, but so far remains undiagnosed. She had minor surgery under general anaesthesia two weeks ago. After being discharged from hospital the next day, she was experiencing hallucinations of strange people in her house, and of her house being a different place. She lives alone and has no children. She is no longer hallucinating but still having noticeable short-term memory problems which are much worse than before.

We were going to visit her for Christmas, but on December 20 she told us she could no longer cope with having visitors, so Christmas was canceled. Since then, she has had at least two occasions where she thought we were still coming. The second time was on December 26 when she rang me to ask when we were coming over (she thought we were there staying in her town). I was able to talk her through it again and calm her down.

She also told me that she had tried to go for a walk on Christmas Eve, and ended up stuck in difficult terrain with her walker. She had to climb up an embankment to a house and get the people who lived there to drive her home. I am the only person she has told about this, but she intends to tell her doctor. On Christmas Day, she said she went for a night-time walk to see the Christmas lights near her home and had a lovely time. I think she is sundowning and getting herself into potentially unsafe situations. I have ordered some name and address labels to stick on her walker in case she is found wandering in the future. She is seeing her primary care doctor again soon, and I think they are aware of some of her recent issues and doing cognitive tests. Thankfully she does not drive.

Her neighbor is supportive but she seems to see me as meddling, and is dismissive of my concerns. She takes her to the doctor but shares limited information with me and seems unaware of the severity of my aunt's cognitive issues. I am backup POA for my aunt. Her main POA is a friend of hers, and I think the neighbor communicates more with him. I have never been in contact with him but I think I will need to do so at some stage. Back when my aunt was appointing her POAs, the friend insisted that she also nominate someone else as a backup option or he would refuse to be appointed, so I think it's likely that he will get sick of dealing with her at some stage and I will need to step in. My aunt also has psychiatric issues and is often difficult to deal with, so they have had arguments in the past.

For now I think that unfortunately I just need to stay quiet and wait for the doctor to diagnose her. I have had bad experiences in the past with doctors disclosing my communications with them to elderly relatives if I do try to pass on information. I feel like if I tell the neighbor about the more recent incidents and memory issues she will see it as lies / meddling and badmouth me to my aunt's POA friend. I think she sees me as burdening and trying to take control of my aunt, and has made some snarky comments about how I shouldn't expect my aunt to do "extra work taking care of visitors". I had accommodation booked elsewhere and I usually do all of the cooking when visiting because she does not initiate it. I also deep clean my aunt's house and throw out all the spoiled food in the refrigerator, and fix all the issues she has saved up for me in the intervening period between visits.

I usually only visit her every few months, but she feels comfortable with me and shares information about her symptoms that she does not tell others. She keeps up a facade with her neighbor and primary POA friend and has more formal relationships with them. I know that eventually the time will come where she can no longer hide things so well, and I feel like my only option is to wait for that.

Everyone says how early diagnosis is important, but in practice I feel like everyone is so uncomfortable with it and just avoids the issue for as long as possible, including doctors. I want to alert everyone to what is happening with her, but I fear that would compromise my relationship with my aunt, and therefore my ability to help her in the future. It just really sucks that we basically have to wait for them to seriously hurt themselves before we can do anything. I wish I could prevent her from coming to harm, but I think it's too early in the process.