David Blackford, Secretary of the Cornwall branch of the National Association of Head Teachers, describes her as "caring". Nothing, he says, was too much trouble for her. She was respected by staff and parents alike and a keen member of his association. "Nobody would ever have been aware of the special circumstances of her relationship with the Prime Minister."
Marjorie used to bring their father, Herbert Wilson, a widower, to Labour Party conferences, where they both became something of a benign institution. I remember her irreverent outpourings at Scarborough in 1967. Harold, she told us, was born the day before her seventh birthday. "I suppose he was a sort of birthday present." Marjorie would talk about him as if he were half baby and half doll, someone to be protected.
Actually Harold Wilson owed Marjorie a great deal, as she it was who was to look after his father and carry many of the family responsibilities. Without her he might not have had the time so assiduously to climb the Labour Party tree.
All was not sweetness and light. As the secretary of the Labour Party Standing Conference on the Sciences and a young MP, Harold Wilson wanted me to talk at length to his father Herbert, who had been a chemist, about the science policy, during the white heat of the technological revolution.
Later, when I told him genuinely that his father had been interesting and his sister charming, he looked quizzically, in a particular Harold Wilson way, as if to say, "That's only half the story." Ever a gossip, he told me that Marjorie had bullied him and recalled that during one summer holiday - I think in Morecambe - he had nearly lost his life at her hands. Going for a walk along the sea-front he and his sister had had a fight. Marjorie overpowered him and hurled him with all his clothes on into the sea. He was terrified and his heavy garments were soaked through. He had to be taken to a shop to get new clothes.
This may have been Marjorie's revenge for all the attention that came to her young brother. As Ben Pimlott put it in his brilliant and perceptive biography, Harold Wilson (1992), "Marjorie was expected to watch Harold's brilliant successes and to be enthusiastic about them, almost as a third parent."
Marjorie's successes were automatically regarded as less of an achievement. There is an oft-repeated story which Harold Wilson would tell against himself. When Marjorie told her parents excitedly that she had won a scholarship to Huddersfield Girls High School, Harold, then four years of age, complained, "I want a 'ship' too." When Herbert Wilson made a celebrated sightseeing trip to London and visited Downing Street, it was Harold and not Marjorie who had a photograph taken outside the door of No 10.
The relationship between brother and sister, however, became very good. When Harold was called to Chequers to see Clem Attlee in 1947, he was staying with Marjorie at her St Austell bungalow (she had moved to Cornwall with her mother shortly after her father started to work there in 1938); they spent the evening making guesses about what Attlee would offer.
Marjorie wanted to know on Monday morning where her brother was to go in the Government, so he arranged to leave a symbolic message on her breakfast table on his way back to Mullion Cove in Cornwall where he used to stay. A lump of coal would mean that he was to be Minister of Fuel and Power, a strip of metal would mean Minister of Supply and a slice of bread Minister of Food. Neither of them had imagined that he would be given the pre-sidency of the Board of Trade.
Marjorie Wilson, schoolteacher: born Manchester 12 March 1909; MBE 1972; died Truro, Cornwall 8 March 1998.