She was born Jessie Wallace, in Glasgow, to an unmarried housemaid. Her first four years were spent with her granny until her mother married. Her parents were brutal, and at age 16 she left home and went as a housemaid in Perth, on Kinnoull Hill, then to three more jobs before returning to her mother, who was now living in Dundee.

In August 1912 she met Fritz Jordan, who was working as a waiter in the Royal Hotel in Dundee, married him in Hanover and had a daughter whom they named Marga Wilhemina after the Kaiser. Fritz died in 1918, and Jessie came back to her mother in Perth; soon she returned to Hamburg where she re-married. Her new husband was a German Jew called Baumgarten; the marriage was unsuccessful and they were soon divorced. She had three hairdressers’ shops in Hamburg, but was forced to liquidate when her daughter’s ex-husband, to whom she had lent money, went bankrupt.

So in 1937 back she came to Perth to housekeep for her widowed step-brother William Haddow. But by then she had been targeted as an agent by the Abwehr (German Military Intelligence) and recruited just before she left.

Jessie was a solidly built, blonde woman, an elegant dresser and a person who wanted excitement and esteem. She was said to be “strong-willed & strict but capable of great kindness and generosity.” But she wasn’t a very good spy. She sent back information on an arms depot near Rosyth, Southampton docks, Aldershot, Scottish east coast defences etc, but nothing very useful.

She bought a hairdresser’s shop in Dundee in Sept 1937 (Jolly’s Saloon in Kinloch Street, price £70) to use as cut-out address for information from USA. Business was not good: she was trying to run a grand establishment in a poor district. Carelessly she tucked maps she had drawn for the Abwehr in amongst shop paperwork, and her shop assistant Mary Curran became suspicious of mail with German stamps and her frequent absences.

In March 1938 she was caught, found guilty and imprisoned in Perth, initially for four years. A year later her daughter died during an operation, leaving a grand daughter, Jessie. Jessie senior was transferred to Holloway during the war, where she became a Christian Scientist. In 1945 she was repatriated to Germany, where she “became a missionary for that cause”. She died in November 1954, having refused treatment.