I'm Team Astrid, as long as she is leaving ample space for pedestrians, wheelchairs, mobility scooters, pushchairs etc.
I rather think her neighbour may have shot themselves in the foot, as the council could decide to come along and instal bollards to prevent her from driving across the pavement on to her paved front garden - or even a strategically-placed new traffic sign.
Legally, Astrid and any of the neighbours can park right outside and block access to what the neighbour believes is their 'drive'. They should be really grateful that they're leaving them sufficient room to (illegally) use it, if parking is at such a premium; not be complaining about somebody overlapping a tiny bit at the side that they wouldn't need to drive over to park there in the first place.