My 84-year-old mother lives alone. Her daily tasks are becoming overwhelming and she keeps asking the same questions. I'm concerned. What's going on with her?

I agree with Lilliput on this one-----my Mom was about the same age as well-and was not all that focused-and would repeatidly ask the same questions. In her case it was the downfall of AD...You may want to have your Mom checked out by her physician or a neurologist-as it may just be simple aging...
Hap

My Mom is in the same situation although, mentally, she is okay.
It could be many things that have sparked your Mom's forgetfulnes: the onset of dementia, something as simple as a UTI or other infection, or just lack of mental stimulation from living alone.
Does she have activities she can do? Does she get out at all? Do people visit or call? I think that docs over-diagnose mental conditions when, really, seniors are just left alone too much with nothing to engage their minds.
just a thought...
Lilli