hi
@Mandagarth
you do seem to be doing all the right things, and unfortunately it's not at all uncommon for people to resist arranging POAs - I think none of us want to consider that they will ever really be needed
I wonder whether your mum would be more willing if she saw it as just something any sensible adult does, especially if they have some assets eg savings, a house ... and children, so that if they had to go into hospital the Attorney did have the Authority to help with bank accounts (rather than focusing on the Alzheimer's) and if you seemed to be putting yours in place too with her as one of your joint and several Attorneys - do have more than one Attorney, and a named replacement if possible, for 'just in case' anything happened to an Attorney (none of us know what is round the corner)
with regard to the phone calls - is there a way to not take all the calls? - maybe record a soothing message on your answerphone, so that you can at least screen the calls and choose when to call back - if you know your grandma is safe and calling for reassurance rather than actual help, and that she won't do anything untoward if you don't answer straight away, then you don't NEED to reply every time - in fact sometimes, I found with dad, answering every call just led to him calling more and being more demanding
if at any time you believe that it's right to move your grandma into a care home, call SS for a best interests meeting and give your evidence - she's already receiving the max 4 home care visits a day - I wonder whether asking for some days at a day care centre would give her some social interaction, a good meal, and tire her out; and your would know that she is looked after and monitored when she is at the day care - or maybe a sitter to be with her a few hours (you might say it's a friend of yours/your mum's who thought s/he'd pop in as you just aren't close enough to do so?