To a journalist, a one-off event is an exceptional, anomalous moment. However, two such occurrences make an emerging trend.
It was the arrival of a new fish shop in a nearby small-scale high street that triggered her Damascene conversion.
And at the moment she says she's doing well, feeling good about putting her money where her mouth is, as well as saving a little money.
It's not without its other costs though.
"I know that people complain about going to the supermarket, but I do miss it a bit. The whole ritual of getting into the car, parking up and then choosing everything at once, there was something quite enjoyable about the whole thing."
She is – probably to her credit – less dogmatic than me, in that she will go to supermarkets if necessary. I, on the other hand, have not been to one for some three weeks now, and will not enter one again for as long as this experiment lasts.
It is a curious coincidence that we both chose to give up supermarkets at the same time. Obviously we share a cultural background, and so look at the world in much the same way, and that explains some of the coincidence.