Parking spaces

Mods if there is a more appropriate forum for this I apologise, please move it.
Hi
Just wanted to get some opinions on an incident.
My 85 year old mother lives alone in bungalow in a small but packed suburban estate in a medium sized rural town. She doesn’t drive a car.
She has a quite large front, cobblelocked, including a drive way.
On Friday morning she woke at 7 and went as always to the front of the house to draw back the curtains and lift the blinds. It was still dark.
To her great surprise and some alarm there was a bronze 171 Santa Fe parked on her driveway, reversed in, pulled up as far as possible, complete with wing mirrors folded in and a frost protector on the windscreen.
She waited for a few minutes then carried on with her routine, returned to the window at 7.20, car was gone.
At this point I’ll say that the road is filled with cars every night from 6.30 on, especially in the last fortnight because the lady 2 doors down is sadly terminally ill and her family are sleeping there overnight understandably and parking cars on the road as well the usual cars and cars from a neighbouring street where there is no parking.
My mother and I speculated that the car on her drive was associated with this neighbours sad situation but found it strange that none of them had knocked on the door to mention that they’d like to park.
Roll on to this morning and she woke at 6 to find the car right back on the driveway. She hovered around the window, as cold as it was, determined to uncover the phantom Parker.
Lo, at 7.15 arrives a tall stout lady in her 50s who commences getting her car ready to leave.
So my mother goes out and the lady looks at her quizzically but says nothing and my mother says “hello. I live here”. She described herself as “a night nurse in this road” but when my mother asked her where she said that was “confidential”. She said she simply couldn’t find anywhere else to park her car.
My mother told her that she had frightened her, the woman said she was sorry about that but had “assumed” the house was empty.
My mother’s house looks anything but empty. There are lights on and off, blinds and curtains up and down and the whole place is maintained to perfection.
The exchange ended with the lady asking my mother if she could park tonight and my mother agreed for her neighbours sake but there wasn’t any kind of apology for not asking permission and it’s all a bit strange.
How would you guys have dealt with this?