The Christmas after her husband died, Charlotte Simpson went on holiday with her daughter. In their tour group to Morocco were two women who travelled alone. “I felt sorry for them,” Simpson says, laughing. “It seemed preposterous. I would ask them from time to time how they felt and they just loved it. Both ladies said: ‘Seeing you here on the trip, I think you’d really enjoy it.’ I was like, ‘I don’t know what makes anybody think I’d like to be by myself on a trip!’”

On her next holiday, Simpson went to China with her sister-in-law. There, they met a woman who was celebrating her 80th. “And she was alone. She had a real spirit of adventure. A very cool lady.”

For the following trip, Simpson booked to go to Italy. She invited friends and family. “Nobody wanted to go. I started thinking about the 80-year-old lady, and the ladies on the Morocco trip. They all had a nice time and nobody ever seemed sad, so [I thought] I’m going to just give it a try.”

Arriving in Italy alone was “a huge traveller’s life lesson”. Her luggage went missing and took 11 days to show up. But she became friendlier and more outgoing. “I just had the best time.”

That was in 2009 and since then Simpson has often travelled alone, sometimes joining people she met on previous trips, writing a journal as she goes, making lists of other places to visit, sometimes planning the next trip while returning home to Illinois from the last, feeling “energised and exhilarated”.

Charlotte Simpson in the Galápagos.

She met her husband at college when they were teaching. Although “a frugal couple”, she and her husband, Roy, made it to all 50 US states, including visits to family (he had 12 siblings) and conferences when he was a school principal. But the international trips Simpson has made alone long ago outnumbered the journeys she made with her husband during the 31 years they were married. Of the 80-plus countries she has visited, she has gone to at least 60 by herself and now encourages other aspiring lone travellers, posting about her adventures as Travelling Black Widow to her 17k Instagram followers.

In some ways, Simpson – whose age is a closely guarded secret – is fulfilling a childhood dream. In her youth, she longed to be an air steward, and even wrote to TWA and PanAm for their requirements, but her grandparents were “devastated” by her plan to leave college early, and she “just couldn’t do it to them”.

Growing up in Rockford, Illinois, her earliest experiences of travel came vicariously through other people’s holidays. “My mother worked as a cleaning lady for a really wealthy family, and every year they would bring back souvenirs, trinkets and candy, for my little sister and me,” she says. “I thought: ‘Oh God, I want to be going to those places.’”

In those days, holidays mostly meant driving south with her grandfather to check on his property in Alabama. As a child, Simpson was aware of the Green Book, with its guidance for motorists of colour. The family’s journey was punctuated just once, by “a big square building” with a sign that said “‘Coloureds Hotel’. I used to so look forward to seeing it on the highway,” she says. “Travel wasn’t open to us.”

Perhaps those experiences added extra force and meaning to her travels now. “I hadn’t thought of it that way,” she says. But then she starts to recall her recent stay at the Grand Hotel Continental in Bucharest. “It had this huge staircase, and I remember going up that staircase and thinking: ‘Wow! I wish my grandmother and grandfather could be here, because we would be together on those drives down south and wouldn’t be able to stay anywhere, and here I am in Romania in this fabulous hotel, on this grand staircase, and nobody is assuming that I am the maid.”

But there is one life journey that Charlotte started with Roy which she has yet to complete. Each spring break they went somewhere warm “with the idea of checking it out for retirement”. They were in Costa Rica when Roy had the illness “that ultimately indicated he had cancer”. But, while Simpson loves to travel, in the 13 years since Roy died, she has found it impossible to find that place “to settle”.

“That’s just something that’s ongoing for me,” she says. “I never imagined having to relocate alone. For now, I just stay here in Illinois and this is my base. I might be here till I’m a little old lady.”