McKechnie began her career when the BBC resumed TV broadcasts after the Second World War.
On BBC Children's Television she narrated the earliest live editions of Andy Pandy from 1950, in which she told a story as it was acted out by string puppets.
The programme was aimed at very young children under primary school starting age of five years at the time.
When the broadcasts began, the main BBC transmitters only covered London and the southeast from Alexandra Palace, Birmingham and the Midlands from Sutton Coldfield, and Manchester and the northwest from Holme Moss.
Other TV work was Focus, 1958 to 1960; Picture Book, 1963 to 1965; narrator, Andy Pandy, 1970.