My mother does extremely well in memory tests. Indeed her latest test, taken at home so an easier environment, showed her memory improving, and not far off normal. Clearly not the case as it then became apparent that she was not sure who I was.
Right at the start we were warned that individuals with high IQs (my mother won a scholarship to read maths at Oxford from a very ordinary northern Grammar) were often able to marshall whatever memory they had left to ace the tests. Her conversation is similarly convincing, though she may not understand the content of the conversation and certainly wont remember anything afterwards.
It must be so difficult for spouses. No real respite, and a sense of loyalty. My mother fades in and out. A couple of months ago she surprised me by showing appreciation for what I have been doing. But the last couple of visits have been difficult. Since she is not sure who I am I am this bossy person who insists on sorting out her laundry etc. More of a problem is that this dislike for 'interfering' people seems to be spreading to carers, whilst her insight into her problems and diminishing capacity is falling. So she is more convinced than ever that she would be fine if we all left her alone.
In response to your question it sounds as if the priority will be to focus on your mum and her need to have some respite and ... some fun.
I would be tempted to phone Social Services, perhaps anonymously, and explain that your mother is being ground down and you are worried about the unrelenting burden and possible carer breakdown. What interventions are possible. A good SS will be able to suggest self funding as well as LA funded options.