FORTUNE — On May 18, moments before what would become a badly botched initial public offering, a Zuckerberg joined Facebook chief financial officer David Ebersman at NASDAQ’s opening bell. But it was not Mark Zuckerberg playing master of ceremonies in Times Square. The company’s founder rang the bell remotely from headquarters in Menlo Park, California. This was Randi, the founder’s publicity-savvy older sister and former colleague, helping launch the company.

Facebook’s (FB) IPO marked a milestone for the maturing social network. But Randi Zuckerberg’s appearance also served as a kind of coda, the end of the first act for Facbeook’s earliest employees. Much has been made of the so-called Facebook Mafia, alumni of the company that have spread across the Silicon Valley and the country buoyed by its incredible cachet, not to mention newly created wealth. Former platform manager Dave Morin started buzzy mobile social network Path. Ex-CTO Adam D’Angelo and engineer Charlie Cheever formed the question-and-answer site Quora. And most recently Sean Parker, the company’s early president, launched Airtime, a video chatting application.

If there is a Facebook Mafia, Randi is a caporegime. She left Facebook last August to start her own social media firm, R to Z Media. (The name is a play on her initials.) It attracted early attention from the like of AllThingsD and the New York Times and Silicon Valley buzzed with curiosity about the other Zuckerberg’s next act. But details on the company have been scarce. With its one-year anniversary just weeks away, R to Z has kept a mostly low profile. This spring the company changed its name without fanfare to Zuckerberg Media. A representative declined to comment for this story. But through public updates and social media activity, early hints of the company’s purpose emerge.

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The studio has worked with Cirque du Soleil publishing videos as well as with fashion e-commerce company BeachMint. Zuckerberg’s firm has also worked with the Tony Blair Faith Foundation and the UN Foundation. (Zuckerberg is a member of the UN Foundation’s Global Entrepreneurs Council.) The company has filmed interviews with celebrities such as Jared Leto and Mandy Moore; Zuckerberg co-hosts a web video series on parenting called “Mom Up” with friend Soleil Moon Frye, the former child actress who played the titled character in the 1980s sitcom Punky Brewster. “She’s a very creative person with a lot of out of the box ways of getting ideas out,” says Victoria Ransom, founder and CEO of Wildfire Interactive, a social media marketer that worked closely with Zuckerberg’s Facebook team.

Zuckerberg Media has also produced video streaming events such as the “Managers Hack” digital music hackathon at the South by Southwest festival in mid-March, which was streamed live in Times Square. Such streaming has interested Zuckerberg since her time as her brother’s marketing chief, during which she piloted Facebook Live, the platform’s “official live video streaming channel” that launched in 2010. When President Obama participated in a town hall over Facebook Live in the following year, it was a major coup for Zuckerberg. “She certainly grew [Facebook Live] from nothing to what it is,” says Max Haot, co-founder and CEO of Livestream, a video-streaming platform that partnered with Zuckerberg on the technical requirements of streaming the events. “We didn’t know how it would go after she left.”

Not only did Facebook Live survive its creator’s departure, but Livestream has gone on to partner with Zuckerberg Media on some ten projects since. According to Haot, Zuckerberg Media has focused initially on helping brands stream their events, but he sees the company’s developing identity as a boutique firm offering companies like Cirque du Soleil packages of video production. “She’s building a studio, so maybe we can share clients,” Haot says.

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Zuckerberg herself is a kind of social media celebrity. To keep that status, Zuckerberg maintains a busy schedule, appearing as an expert at events around the world. Those have included a networking conference held by the National Association of Professional Women in New York in May, conferences in Paris and Luxembourg in June and a conference with Air New Zealand in Auckland on July 4. Zuckerberg typically uses such appearances to discuss her time at Facebook and the process of starting her own company — avoiding specifics. Then there are the less congruent appearances: hosting an annual Shabbat dinner in Davos or speaking at a jewelry industry event in Scottsdale, Arizona.

Zuckerberg’s business interests aren’t limited to her own company, either. She serves as an executive producer of a reality television series announced by Bravo in April, “Silicon Valley,” which remains in development. And she has turned investor like many of her peers, advising and putting money into travel startup Trippy. Zuckerberg’s war chest for such ventures is considerable: while Zuckerberg earned almost $360,000 in compensation at Facebook from 2009 to her departure in 2011, according to Facebook’s S-1 released before its May public offering, that filing did not disclose her presumed millions in stock holdings (Zuckerberg famously had to be convinced by brother Mark to take stock over just cash six years ago when she joined Facebook as an early employee). Her husband Brent Tworetzky serves as a director at online textbook company Chegg.

So what will Zuckerberg Media really be? It’s impossible to say for sure, but there’s no question that she has the resources and profile to make her mark alongside Facebook’s other notable alums. “I think they are repeating the PayPal mafia,” says Patrick Salyer, chief executive of social infrastructure company Gigya, a Facebook preferred developer. Salyer is referring to the group of former PayPal executives such as Peter Thiel and Elon Musk who have since founded and invested in successful companies. That’s a tall order to live up to. Still, the first act wasn’t too shabby.