Get the PoA done ASAP if you still can.
One of the questions to be certified by a friend or neighbour is "Is this person still of sound mind... or similar"
In June 2019, I was making an annual visit my sister, I live in Switzerland, I saw that she was seriously having memory problems, not just repetition. I went with my then 81-year-old sister to a solicitor we fortunately vaguely knew. Whilst we were there, my sister said, "why are we here, is it about the will". The solicitor and I exchanged glances and I explained, again, why. OK, we completed the PoAs in both health and wealth and they cost us then around 500 for both. The registration was done by the beginning of September, but then I needed to fly over to go to the bank personally in December, to get full banking access organised. I also submitted my PoA to the GP at this time, fortunately, later this more direct contact came in very useful. From that time on, I increasingly used the PoA to take over all running aspects of my sister's life.
Covid came and I had to do everything remotely. Fortunately, with the modern day registered PoAs, you can send most companies a link to view your registered PoA for 30 days. Only in very few circumstances, Lloyds Bank and NS&I? did I have to send signed registered copies of the registered PoAs, which again cost about 65 Pounds.
After 4 rather consuming years, my sister passed away back in July 2023, fortunately without physical pain, just mental frustration and the inability to eat and speak anymore. Without the PoAs in place, I don't know what I would have done.
My advice, don't try and save £, save time, go to a solicitor, just get it done, you need watertight PoAs.
Just one more thing, your PoA ceases when the PwD passes away. Use your PoA to simplify the finances towards their EoL, document their assets. I researched various ideas in this
topic Funeral Preparation Checklist and created a Probate Inventory list, which greatly simplified matters.