You say you don't think she's quite at sheltered housing point yet but its definitely something she will need in the future.
If she lacks mobility, motor control, is wheelchair dependent and has continence issues, who is providing the personal and social care for her on a daily basis (personal hygiene/intimate care, laundry, shopping, cooking etc)?
Sheltered housing has many different types, anything from fairly independent living for the 50+ where a warden visits once a day, semi sheltered care which can involve the residence having their own apartment but wardens on site, and very sheltered housing.
I had a quick look at my local housing association that is for the over 50s and they offer housing with care, supported housing, sheltered housing and very sheltered housing as the types they offer. Another local housing association has similar tiers - enhanced sheltered, extra care and close care for the types of properties they manage.
I am a carer for a lady in her 70s with mobility issues. When she had greater mobility a few years ago, I took her to view a lovely studio flat in a great care home that had its own cooking facilities and TV which was in the nice part of town and right next to her beloved bus route. She could have joined in the social activities and enjoyed cooked meals in the other part of the property if she wished or kept herself fully to herself.
As it happens, she was disgusted and disappointed with what was on offer and turned it down. As a result she has now suffered in her own general needs housing association flat that she's been unable to leave due to steps for over a year, feeling very isolated and lonely which then led to poor mental health, poor personal hygiene and issues relating to nutrition as she can't cook for herself.
As you are finding out, some people are resistant to taking responsibility for their well-being and cannot make any changes that would improve their well-being, or see the impact of the way they run their life on the others around them.