A friend of mine has her dad with dementia living with her, and hires a live in carer for when she has breaks away, or actual holidays. It seems to work well in that the dad doesn't really notice it isn't his daughter and 'accepts' the situation. Though she reports that he is often a bit more 'difficult' when she does return to take over again, and his dementia can seem a bit worse, so presumably even though he is accepting of the stranger looking after him, it does 'register' somewhere inside. (He's still very mobile and 'superficially OK', likes to try and get out of the house, that sort of thing.)
My friend gets her live incarers from a local agency. She lives in an affluent part of the home counties, and the local agency therefore has some 'demanding' customers, who are used to 'high standards' etc etc, so I think she gets a pretty good calibre of care-worker coming in. That said, they are, I should warn you, mostly non-UK nationals, and with some the pronunciation of English has been a bit tricky - so you have to take that into account for your mum, if she isn't 'used' to multi-cultural environments, or English not being necessarily a first language. Even if the carer is trained, or inured, to the 'odd ways' of their elderly carees, it would be horrible if an elderly client with dementia, grown up in a different Britain from now, was insulting in any way.... (obviously, very much hope this isn't an issue, but bear it in mind as a possibility, given the generation gap)
Another factor to take into account is that the live in care-worker is just that - they are they to care....not to do housework! So you may find it necessary to hire a cleaner (if you don't do it yourself of course!) as well.
I do wish you all the best - it is SO difficult, I know from my own experience, when one of the parents becomes too 'acopic' to keep going on their own. They need 'someone else' with them all the time.
One limitation of a live-in careworker, however, may also be that although they are there to provide the physical care, from toileting to laundry to cooking to taking out and about (my friend's father's care workers will go off for walks with him, down to our local café), they may not provide what could be called 'company'.....you may well already have experienced this with your mum, that I did with my MIL, that for example, they can't actually watch TV 'by themselves' any more, in that it doesn't make sense to them, so you need to sit with them and chat them through the programme, and interact with them, telling them what is going on and so forth. Would a live-in carer do that? (Not sure how deep your poor mum's dementia is?)
The whole situation is, though, desperately sad. I would also suggest that it's a sensible idea to have a 'forward plan' for if your mother's condition deteriorates to the point where she does need a nursing home (my MIL needs this now), and whether nursing care could be 'live in' or require residence elsewhere.
Wishing you all the best in finding what you are looking for - it's all so sad, isn't it?
