But Green, who has died aged 110, was the last known surviving veteran of World War I. She was serving with the Women's Royal Air Force as a waitress at an air base in eastern England when the guns fell silent on Nov. 11, 1918.
It was not until 2010 that she was officially recognized as a veteran after a researcher found her service record in Britain's National Archives.
Green died on Saturday at the Briar House Care Home in King's Lynn, eastern England, two weeks before her 111th birthday, the home said.
Retired Air Vice-Marshal Peter Dye, director-general of the RAF Museum, said it was fitting that the last survivor of the first global war was someone who had served on the home front.
"In a way, that the last veteran should be a lady and someone who served on the home front is something that reminds me that warfare is not confined to the trenches," Dye said.
"It reminds us of the Great War, and all warfare since then has been something that involved everyone. It's a collective experience ... Sadly, whether you are in New York, in London, or in Kandahar, warfare touches all of our lives."
She was born Florence Beatrice Patterson in London on Feb. 19, 1901, and joined the newly formed Women's Royal Air Force in September 1918 at the age of 17.
The service trained women to work as mechanics, drivers and in other jobs to free men for front-line duty. Green went to work as a steward in the officers' mess, first at the Narborough airdrome and then at RAF Marham in eastern England, and was serving there when the war ended.
Decades later, Green remembered her wartime service with affection.
"I met dozens of pilots and would go on dates," she said in an interview in 2008. "I had the opportunity to go up in one of the planes but I was scared of flying. I would work every hour God sent. But I had dozens of friends on the base and we had a great deal of fun in our spare time. In many ways, I had the time of my life."
After the war she stayed in the area, raising three children with her husband Bob Green.
Once her service record was rediscovered, the RAF embraced the centenarian veteran, marking her 110th birthday in February 2011 with a cake.
Asked what it was like to be 110, Green said "It's not much different to being 109."
She praised the officers she had served during the war as perfect gentlemen.
"It was very pleasant and they were lovely," she said. "Not a bit of bother. They kept us on our toes and there was no slacking."
A delegation from the air base had been due to visit Green on Feb. 19 to celebrate her 111th birthday.
"When we heard the news there was a palpable silence, because we all hoped she would make it," said Squadron Leader Paula Willmot.
The war's last known combatant, Royal Navy veteran Claude Choules, died in Australia in May.
After his death, Green became the war's last known surviving service member, according to the Order of the First World War, a U.S.-based group that tracks veterans.
Andrew Holmes of the Gerontology Research Group, the researcher who found Green's service record, also said she was the last known survivor of the conflict - and the sixth oldest person in Britain.
Green's husband died in 1970. She is survived by two daughters, a son and several grandchildren and great-grandchildren.
The date of her funeral was not immediately known, but Willmot said air force personnel would attend, and the RAF Association would provide a bugler and a Union Jack to drape on the coffin
"It will be a real send-off for her," Willmot said.