When Chiara Ferragni joined the board of the Italian luxury brand Tod’s, the company’s stock rose 12 percent. Ms. Ferragni is a 34-year-old mother of two with more than 26 million followers on Instagram, and one of the world’s most famous fashion influencers, particularly in Europe. Her businesses include a clothing brand and a talent agency.

Not bad for a former fashion blogger still sometimes known as “the Blonde Salad” — though few people still use the word “blogger.” If they do, it is usually a mistake. What they likely mean is “influencer” or “creator.”

These words are essentially the same, though — just adopted at different moments in recent history. They are all people who make content online professionally while drawing from their own lives: their outfits, their engagements, their sponsored vacations, their passion for cryptocurrency. Twenty years ago, this content was published on platforms like WordPress, and its reach was difficult to quantify. Now it’s largely on TikTok, where the metrics, including likes, comments and shares, are much more accessible.

Had Ms. Ferragni not started blogging in 2009, it is possible that so-called creators like Addison Rae, the 21-year-old nascent actress with 86 million followers on TikTok (the app’s fourth most followed account) would not be sitting in the front row at Michael Kors last Tuesday — the most glitzy show of New York Fashion Week — a few feet away from Ms. Ferrangi.

That’s because Ms. Ferragni was among the first wave of bloggers to disrupt the fashion industry. At the time, a post from her or Bryanboy or Garance Doré could carry the advertising weight of a page in a glossy magazine. As these early influencers began attending runway shows, they soon sat with the once powerful editors of those glossies.

For a long time, the fashion establishment was not amused by this arrangement. “People were once snobbish about anything coming from the internet,” Ms. Ferragni said, sitting in the lobby of the Bowery Hotel last week, as New York Fashion Week ended.

But this means she is also no longer the hot up-and-comer with something to prove. (One critic described her last week as the “Mother of Dragons” of influencers.) Ms. Ferragni enjoys watching TikTok videos, for example, but hasn’t figured out her role on the app, attracting only one-sixth of her Instagram following.

“I sometimes do TikToks, but I’m not, like, a TikToker — it doesn’t always feel like myself” she said. “It’s OK to say: ‘Maybe this is not my platform. Maybe it’s not something I want to do.’”

The Family Business

So how does a longtime social media personality secure her legacy, if not by conquering new platforms? She follows the Calabasas playbook.

Last year, one of Amazon Prime’s top original series in Italy was the reality show “The Ferragnez,” starring Ms. Ferragni and her husband Fedez, an Italian rapper who proposed to her onstage in 2017. Their wedding coverage in 2018 rivaled that of Harry and Meghan, and they invited cameras into their marriage counseling sessions during their show’s first season. “It’s important to not always portray a happy perfect life,” Ms. Ferragni said.

Also starring on “The Ferragnez”: her novelist mother (630,000 followers on Instagram), her dentist father (125,000 followers) and her sisters Francesca (1.3 million followers), who is 32, and Valentina (4 million followers), who is 29.

Ms. Ferragni doesn’t consider it strange that any of them have amassed a following. Her followers simply “love the lifestyle,” she said. “They don’t just like you. They are interested in everything that is connected to you,” which includes family members and friends.

Only her youngest sister has followed her into fashion; in September 2020, Valentina started a line of colorful, gender-neutral fine jewelry that she described as “easy to wear.” Her first design for Valentina Ferragni Studio was a single V-shaped earring charm called Uali, which is her nickname, and which she said was a “tribute to myself.”

The jewelry line has since expanded to necklaces, bracelets and rings, with each design incorporating her blocky “V” logo. The company has just a few employees, all of them women under 30, and said that everything is made locally and handcrafted. It is stocked by 400 jewelry retailers around Italy, as well as the department store Rinascente.

As celebrity sisters typically do, Valentina and Chiara strongly resemble each other — they both have long middle-parted hair, startling blue eyes often lacquered with shiny eye shadow, and candy-colored high-end wardrobes.

When she was 15, Valentina used to take photos of Chiara’s outfits before the Blonde Salad blog even existed, when Chiara was still enraging her fellow users of Flickr, the image-hosting service and social network for photography enthusiasts. Chiara would post on Flickr like a diary, as opposed to, say, sharing sunset photos or close-ups of exotic flowers. “People hated me,” she said.

The sisters were raised in Cremona, Italy. Their mother, Marina Di Guardo, loved to take photos and videos of the girls despite having nowhere to publicly share them. Ms. Di Guardo used to work at the showroom for the label Blumarine, so the sisters were aware of fashion from a young age.

But until Chiara’s blogging took off, Valentina’s ambitions were to be an architect or interior designer, she said. She still remembers attending her first runway show in Milan with Chiara, about seven years ago, “shaky because I didn’t know what to do,” wearing a denim jumpsuit and hat as she posed for photos with her sister, whose ease in front of the cameras she desperately wanted to emulate.

Valentina said she still wants to be like Chiara but realizes there are limitations.

“For some people, I’ll always be the ‘second one,’” she said. “But we are different people. We are both blond and we share the same surname, but one is Chiara and one is Valentina.”

An Influencer Empire Expands

Still, when your sister is a fashion mogul and the head of what some Italian media have called its “royal family,” coming in second isn’t the worst thing. While “my surname, until 10 years ago, was just a surname,” Valentina said, it has provided an advantage in a crowded market. Valentina Ferragni Studio said its 2021 revenue was about five million euros.

It’s a market Chiara decided to enter as well, last fall, one year after Valentina introduced her jewelry brand.

“They’re not competitive,” Chiara said. The elder sister’s jewelry is more blingy costume jewelry, all crystals and chains and little heart accents.

Fabio Maria Damato, the general manager of Chiara Ferragni Collection and the Blonde Salad, acknowledged that at first, “the business people were worried.” But it became clear that the sisters were taking different approaches and were running two different companies. (After all, don’t Kim and Kylie both sell makeup?)

Mr. Damato began working with Chiara about five years ago. A former fashion journalist, he appeared in both “The Ferragnez” and Chiara’s 2019 documentary “Chiara Ferragni: Unposted,” as her right hand, helping her both into outfits and out of complicated business situations, such as gaining financial control of the Blonde Salad, which Chiara had founded with an ex-boyfriend.

Even now, as the company actively seeks outside investment, Chiara has no plans to cede control of the company that bears her name. She has, however, in light of the death of the “blogger,” and the fact that people “don’t really go to websites anymore,” ceded the Blonde Salad’s website. The blog has largely stopped posting new content in favor of publishing to Instagram.

“We pondered shutting it down, but we wanted to keep it alive just for the sake of it, because it’s history and part of my story,” she said.

There was a moment, last fall, when that story seemed to reach its climax. While Chiara has been on the cover of dozens of international magazines in the last decade, she finally appeared, in October, in the pages of her country’s storied fashion bible, Italian Vogue.

Vogue Italia’s aesthetic had always been more artistic and abstract, its sensibility more controversial and socially conscious than other editions of Vogue. But earlier in 2021, Vogue announced a new strategy to bring all of its global titles under consolidated leadership.

This led to the elevation of a young woman, Francesca Ragazzi, as Vogue Italia’s new editorial leader. One of her first acts was putting Chiara on the cover of an issue dedicated to “fresh starts,” with Ms. Ragazzi calling her “the ideal protagonist to interpret this new direction.”

To Chiara and Mr. Damato, Vogue Italia’s embrace — at last — was a sign of a larger change in Italian fashion, which has long been ruled by older designers, executives and family-operated companies that can be resistant to what the “next generations” have to say, Mr. Damato said. In Milan, more than in other fashion cities, it’s hard to find success under the age of 45.

“When we were young and starting, it was so tough,” Mr. Damato said. That’s changing, not only because of Ms. Ragazzi’s support of Chiara, he added, but because of a growing network of young designers including Giuliano Calza of GCDS and Gilda Ambrosio and Giorgia Tordini of the Attico.

The older generation in Italian fashion may “know each other and respect each other, but they don’t want to work together,” Chiara said. “Our generation is more supportive of each other.”

This is, Chiara suggested, a new way of doing business in Italy. And it’s good news for her sister Valentina, as she tries to both stay close to her sister and walk her own path.

“I really would love people to understand that we are two different people that have two different businesses, two different societies, two different brands,” Valentina said. “But we help each other. Maybe we’ll do, like, a collaboration one day.”