In 2020, three months after his 100th birthday, Dorothy Wiggins’ husband, Guy, died. They had been married for 61 years. “We never fought,” she says. “We were always together. Without him, I was devastated by grief.” Immediately after his death, alone in her West Village brownstone in New York, she filled her days by putting together a photo album of their life, but soon Wiggins started making trips into the city to figure out what to do next.

One of her children, Noel, had previously commissioned his journalist friend Michael Astor to make a short film about his parents. Now he suggested that Astor could film his mother’s day-to-day activities. It might help take her mind off her bereavement, he said, and Astor could use the footage to create a documentary about her life.

A few months into the process, Astor began posting clips of Wiggins’ Manhattan escapades on Instagram and TikTok. Petite, armed with a wooden staff and always dressed to the nines, Wiggins soon gained a following thanks to the uncompromising takes she came out with while marching about town. She expounds on everything from local dining hotspots to theatrical adaptations of classic musicals and the art of seduction. In one clip, she passionately explains the supposed health benefits of drinking wine with every meal.

A year on from going live as @dorothylovesnewyork, the 98-year-old Wiggins now has close to 100,000 followers on Instagram. She is a social media star but in classic Wiggins fashion, she has an outspoken opinion on her newfound fame. “I think cellphones are a great invention and have made life much easier for everybody but I think social media is stupid,” she says. “People telling things about their lives to strangers is just a jerky thing to do. I’m not a bit interested in it.”

While she doesn’t approve of the influencer lifestyle or check Astor’s posts, Wiggins does find joy in reading her fans’ comments and encountering them on the street. “I’m pleased that people are inspired by my longevity and attitude,” she says. “I used to be a model and trained as an actor so I don’t mind people seeing me or Michael filming me. New Yorkers are very blase – they don’t make a big deal about it.”

Yet one post from the past year does stand out for her. “Nine million people watched my tennis serve and that thrilled me because tennis players are obsessive about the game,” she says. “Women’s champion Chrissie Evert even commented on it! I’ll never stop playing.”

Although she and Astor film most days, Dorothy’s life is largely unaffected by her social media fandom. She still has the same friends and sticks to the “sacred cocktail hour” she would share each day with Guy, a landscape painter and diplomat (her drink of choice is a whiskey with ice, and a glass of water on the side). What Astor captures is the real thing. “I’ve always been very outspoken. If I don’t like something, I will let people know that,” she says. “Guy and I would not take any crap from anybody.”

In fact, the greatest effect of Wiggins’ social media stardom has been on her fans who are moved by her sense of vitality. “I think of myself the same as I’ve always done,” she says. “If you say: ‘I’m old,’ you act old and think old. I just don’t think old. My personality is the same and people still seem to enjoy my company.”

There is no slowing Wiggins down. She will keep filming for the foreseeable future. “There is always a picture to be taken of me doing something,” she says. “Guy would be amused because I could barely get him to start using emails.”

Three years on from his death, Dorothy’s grief has not gone away, but she has learned to live with it. “We had a magical life and it wasn’t enough for me,” she says. “But life carries on and it is never too late to keep up with the times and try something new.”

• Tell us: has your life taken a new direction after the age of 60?