To add a bit of perspective... as stated, my mother had Parksinson's about 15 years, it would have been far less time had Surrey County Council managed to do its worse (she nearly died in a care home, her neglect though mentioned by the CQC in its visit at some length was ignored by Surrey's so-called Safeguarding heads). Part of the reason my Dad couldn't keep his usual eye on her was he'd written off the car on the way back from seeing her. This was in early 2014.
Now, my mother died in autumn 2017, aged 83. My Dad died a month or so ago, aged 94. So he went from in 2014 being able to drive around, do the local shop, cycle a good few miles a day (he'd cycle to the care home for a month or so) to death within less than a decade. He had a whiff of dementia worsening gradually, he never drove again after the crash, he had a fall after the first lockdown, mildly broke a hip bone (it was weight bearing) but - and I curse this - he never really walked again, I should have got him on a sedentary exercise bike and I recommend this for your parent. My point is, Dad did not have Parkinson's. But whatever he had, it got him in a shorter time than Mum's Parkinson's. It became in the end a succession of different things - urinary tract infections, low sodium levels, some kind of epileptic 'crash' that was very odd and increasingly frequent which could only be treated with a sedative that is not a good thing to give an elderly person, constipation, dry skin that led to awful itching and so on. Had be been in a care home instead of cared by us at home, he'd have gone a few years earlier, Covid or no Covid.
So, at the OP's mother's age - something is going to get them. It may take a decade. Or, if there's nothing wrong, it can happen next week. There is a list of famous people - Christopher Plummer, Des O'Conner, Nicholas Parsons, Bobby Moore (albeit he had dementia and was in a care home), Barry Humphries and possibly even Queen Elizabeth, who were at the races and some even full-time working and in their 90s who had a fall and that was it, it was curtains for them. Others will be in a car crash - Bond 'Q' actor Desmond Llewlynn was one fatality, Prince Philip might have been another, so might my Dad all those years ago but no one was hurt.
I'd advise the OP has their parent undergo a bone scan and take Adcal D3 or whatever they advise these days because a fall is obviously more likely to lead to a break if they have low bone density. Look out to get soft furnishings etc avoid hard edges.
And print out the forms for LPA in Health and Welfare from the Govt website to be ready; the signatures need to be witnessed by someone who's known them for a good many years and done in a particular order, it costs around £80, I don't know if Finance costs extra or not, probably.
I attach a couple of letters printed in Metro newspaper this year, the first is from me, but another replies to it saying if you have siblings make sure they're included too though you will know if this might be an issue for your family.