My mother lives in an assisted living facilty, but I try to do as much care as I can due to expense. Lately I will go down to bath her, get her hair done weekly and lay out clothes for her. She will not put on clean clothes. If I am out of town for the week, she has the same clothes on as when I was last there. Is this common among the aged?
Some very old people may change clothes, but skip bathing. They go out, thinking all is okay. They don't realize that other people can smell them. I can understand why some people don't bathe. They are trying to stay alone at home and staying clean can be risky and require a lot of energy. Still, it isn't pleasant to be around someone who smells bad.
You might have her doctor order an evaluation of her ability to perform "adls" activities of daily living, such as bathing, toileting and dressing. In the short term, it's going to be easier to get that kind of assessment than a full neuropsych workup. It will also give you and her doctor a better picture of what her needs sre, going forward.
I pretty much dismissed the diagnosis of vascular dementia for my mom after her stroke until I peaked in and watched her ot evaluate her dressing skills while at rehab. It was a real eye opener.