When does an elder parent need assisted living?

She should see a doctor. Maybe you can get her there for another reason other than the signs of dementia. People often feel stigmatized when someone says they aren't thinking right. That's, unfortunately, due to our society, but it will take time to change.
If she has high blood pressure or any other ailment, tell her the doctor must see her to give her the medications. Then, write the doctor ahead of time (or call if you can get through). Let the doctor know that you feel there are cognitive issues and describe them. It's possible that your mother has a UTI or some medication interaction that is causing these symptoms. However, likely it is dementia. Anyway, the only way to know is to get a diagnosis. Just back off for now when it comes to telling your mother you think she has dementia and try for some other reason to see a doctor.
Also yes, it sounds as though she should be in a memory unit if no one in the family can stay with her (as is most often the case). That is, of course, if there isn't a reversible cause for her disordered behavior. The doctor can help with that, as well.
Good luck,
Carol

Thank you for that. I agree, she needs to see a doctor and get a diagnosis. Your suggestions are good ones.

I know from personal experience with my own MIL that UTI's can hit them really badly and cause a lot of mental deterioration. Whenever she gets one we can tell because there is such a drastic change in not only her behavior but she won't eat or drink anything too. She also only wants to sleep all day. It is a good idea to get your mom into a doctor ASAP. I took my MIL in and they were able to put her on Aricept and later Trazadone to boost the Aricept as well as enable her to get some sleep. She used to be up and down all night, but the Trazadone definately helps with that now.

I agree with the other answers, but also take care of her money. I waited too long. Once they start risking their financial security in ways they would not have earlier, don't wait before you act. Make an appointment with a geriactric specialist (GS). He can become mom's new primary care physician. My experience was that other specialities just are not equipped to handle the special needs of the elderly.

If you have power of attorney, move to protect your mom's assets and contact the attorney that set it up. Keep him in the loop. For instance, when I took mom's silver coin collection for safe keeping, I inventoried it and sent a copy to the attorney. You could even have bank statements sent directly to him. This is important if there is Anyone that may later question your actions.

My mom had similar hysteria about 'being put away'. The ALF required she have 24/7 care for the first 30 days because of it and her threats to burn the place down. That was hard, but between family members and paid caregivers we managed. Thirty days gave her a chance to get used to the routine and make friends. I wouldn't say she loves it, but she is content. I think the change and the unknown is what she really feared and now that it is familiar she realizes there is nothing to fear.