Very bad luck, Geoff. And kudos to you for maintaining a level head. If it was me, I wouldn't be so 'kind'.
I have a next door neightbour who is sounds exactly like the woman who vandalised your car. She thinks it is her "right" to have the two spots outside her house as hers, although she never parks outside. We have had incedents of vandalism for years - from raw fish inside cars to broken mirrors, antennas, glass, and scratches/keying.Oh, and one incident of acid sprayed over the fence onto a new 4WD.
Funny thing is these incidents only happen when cars are parked outside her place, not mine, and only to our cars.
Some serious security cameras and a a few words to the streets gossiper and surprisingly the incidents stopped immediately.