just a few thoughts based on how the story went with my Mum and I.
My Mum lived alone at diagnosis aged 82, and already had a community alarm (after an accident a few years before diagnosis - which we kept going as it gave peace of mind as she lived alone...very reassuring to have one of those!) She decided to pay for a cleaner once a month who gave her house a good clean - which meant I didn't have to do that...
Then she decided to move into sheltered accommodation, not an easy choice but it meant there were other people around without having to go outside, her flat was smaller - no stairs to cope with, the flats were closer to shops, church etc and it actually increased her independence and she worried less about being alone. Also no garden/maintenance jobs to be done. The warden was there to sort out problems with taps/light bulbs/ etc etc. She joined the group of people organising the social events they had in the lounge regularly.
Being independent in her own flat, but with others nearby and the emergency call system to call the warden - in an emergency was brilliant. She kept on catering for herself, doing some chores and being as active within her community as she wanted to and with other residents of the sheltered accommodation.
My friend's mother had a live in carer for a while and I recall that they had to organise a room for the lady as there are specific requirements you have to meet...can't recall what they are - sorry! I also recall that there were difficulties at times with the carer's day's off. It is not cheap... I think my friend used it as a care system when she went on a holiday and so would not be around for her Mum.
so I haven't really answered your question but having been through making these hard decisions thought I'd share the positives of sheltered accommodation.....Go and have a look and see what they are like in your Mum's community - to keep her in touch with her friends etc....
My thoughts for you! Hope they help - even to simply confirm what you don't want!!