Janet Brewster was a postwoman who had a brief chat with Martin Platt while delivering the day's post to the Builder's Yard in January 1989. Martin attempted to flirt with the young woman, remarking that she was an improvement on the one yesterday as he had awful legs. He then asked her name, which Janet gave him, raising her wedding hand - "Mrs. Janet Brewster".

Among the letters delivered by Janet included confirmation of Alan Bradley's £15,000 loan from the Castlewell Building Society. Unaware of the letter's contents, Martin joked to Alan about the slowness of the post office, the letter being address to the long deceased Len Fairclough, whose identity Alan was using in order to get the loan.

The character was credited as "Postwoman". Her name was given in dialogue.