Quote Originally Posted by psychopixi
I'd call the RSPCA, or whatever society you have over there that's involved in animal welfare. Report the woman for threatening to poison the cats, and ask if the society could come and take the cats away and re-home them.
that would be the best thing to do IMO. if you do something to the old woman you run the risk of being arrested besides if shes old like you say she'll die soon anyways.