https://en.wikipedia.org/wiki/Nicholas_Fisk#Grinny

This was a well-known science fiction book I remember reading as a kid in the 80s at school. I recall it being made into a British kids TV series as well, with a limited number of episodes, but I'm damned if I can find any record of it anywhere - yet I know it was screened on TVNZ. I remember the old woman saying "you remember me?" over and over to the adults and it put them into some sort of trance, but it didn't do anything to the kids around her.

Did anyone else see this series in the mid-80s? Was it actually named Grinny, or You Remember Me (the name of the sequel)? Google doesn't tell me much sadly, nor does the IMDB. I'd like to see it again if possible.