At the outbreak of war, Herbert worked in the British Embassy in Warsaw and then as a civilian translator in the Air Ministry in London. She joined the WAAF at RAF Innsworth on 19 September 1941 as a General Duties and Intelligence Clerk. She was released at her own request from the WAAF so she could join the SOE in March 1942.
SOE training
In May 1942 Herbert joined the SOE. She was the first WAAF officer to volunteer, as she had been granted a retrospective commission with the rank of section officer dated from 15 January 1941. Herbert trained with the second group of SOE women agents, including Odette Sansom, Jacqueline Nearne and Lise de Baissac. They did not go to Scotland for training, but were predominantly trained at Special Training School 31 at Beaulieu. Peter Churchill's first impression of Herbert was that she was too fragile for the rigours of Resistance life. She was tall and slim with fair hair, religious, well educated and had a degree in art. She was also 39 years old when she joined the SOE.
Mission in France
Following her training, she landed by felucca off the south coast of France, having travelled from Plymouth via Gibraltar on 30 October 1942. On arrival in France she travelled to Bordeaux to act as a courier to the Scientist circuit, using the codename Claudine. She traveled by bicycle and train, liaising with the different groups within Scientist, carrying messages, acting as a 'post-box for the members of the circuit and also seeking out safe houses and potential recruits. Additionally she helped to arrange and was present at parachute drops. Whilst working in France, she met fellow SOE Agent in the Scientist circuit, Claude de Baissac, by whom she had a daughter in December 1943. The child, named Claudine after her mother's codename, was born by caesarian section at a private nursing home in La Valence, a suburb of Bordeaux. She then moved into a flatlooked after by fellow SOE Agent Lise de Baissac.
Arrest
On 18 February 1944, Herbert was arrested in Poitiers. The Gestapo had found out that the flat was maintained by an SOE Agent, and they initially thought that Herbert was Lise de Baissac. She was separated from her baby daughter and the child was looked after by the French Social Services. She created a cover story for herself that she was Madame Marie Louise Vernier, a Frenchwoman from Egypt; she protested her innocence saying she knew nothing of the woman who owned it and had only been there a few weeks. During the few months in prison, the Germans learnt nothing from her but she endured the harsh conditions. She was released at Easter 1944 and after, arguing with the authorities at the orphanage that she was wrongly arrested, reunited with her child. Herbert then hid in a small country house near Poitiers until the end of the war with her daughter. In September 1944 she was reunited with Claude and his sister Lise de Baissac was part of the Judex Mission.
Honours and awards
She was awarded the Croix de Guerre by the French, but unlike her contemporaries, received no British award.
Post-war life
Herbert and Claude de Baissac were married in November 1944 but never lived together. She gave French lessons privately. On 23 January 1983, Herbert died of pneumonia at her cottage in Frant, Sussex with her daughter at her side.
