(Reuters) - When COVID-19 struck and top insurance recovery litigator Robin Cohen found herself logging 14-hour work days from home, she had a revelation.

All the trappings of Big Law, the infrastructure and the fancy offices? It wasn't necessary to do her job - that is, representing policyholder clients that have included Pfizer, Verizon, CBS, American Airlines, Madison Square Garden and The Carlyle Group in litigation against insurers. Over the years Cohen has won more than $5 billion in recoveries and a wide range of industry accolades, including a spot on The National Law Journal's 50 most influential women lawyers in America list.

The longer Cohen and her colleagues in the tight-knit insurance group worked remotely, "The more we said, 'We really don't need a big firm,'" she told me. "We realized we could forge our own path and focus on the issues that we want to and are passionate about."

Last week, she cut the cord with McKool Smith, launching 12-lawyer Cohen Ziffer Frenchman & McKenna. Cohen serves as the firm chairwoman, and Kenneth Frenchman is managing partner of the New York-based boutique.

McKool Smith founder and chairman Mike McKool was gracious about the departure. "I understand as well as anyone the impetus and excitement about creating one's own firm," he said in an email. "It's what we did 30 years ago. I'm sure Robin and her team will have success, and we at McKool Smith wish them the best."

The move earns Cohen entree into an exclusive (albeit unofficial) club: top women lawyers who ditch Big Law to launch or co-launch their own firms.

Beth Wilkinson did it in 2015, for example, as did Roberta Kaplan in 2016, Faith Gay in 2018 and Andrea Mitchell in 2019.

Are we looking at a trend?

Mitchell, who quit Buckley LLP to form 11-lawyer financial services boutique Mitchell Sandler, hopes so.

"The more women who do this, the more momentum we generate," she said.

Her advice? "Start before you're ready," Mitchell said. Don't wait to assemble the perfect book of business, team of associates, office space and back-office support, never mind the other niggling details.

"Look at getting the core building blocks in place, and the rest can come later," she said. "There are very few things you need on day one."

While women have been going to law school in roughly equal, and some years greater numbers than men for more than a decade, Cohen noted that in Big Law, there are still "very few women equity partners, and they're often at the bottom of the chart, bunched up together," she said. "One way that will change is when women leave Big Law and start their own firms."

But it takes guts.

"Given the endemic sexism and racism in the world, it's my experience that women and minority lawyers often tend to be more risk-averse in our careers - and it's completely understandable," Kaplan, who left Paul Weiss to found Kaplan Hecker & Fink, told me.

She likened launching the litigation boutique in July 2017 to "taking a giant leap over a canyon." The firm has grown from four lawyers to 43, with headquarters in New York and a new office in Washington D.C. Its high-profile cases include a defamation suit against President Donald Trump on behalf of writer E. Jean Carroll.

"It turns out that there's a lot of demand out there for a litigation boutique that operates at the level that we do - and there's a greater openness and appreciation by clients of the clear advantages of having a diverse team representing you," Kaplan said.

Cohen and her colleagues were well-positioned to break away from 130-lawyer McKool Smith, where she headed the insurance recovery group.

Their practice during the pandemic has been thriving, she said. About 10% to 15% of the current caseload is COVID-related, as businesses seek payment from their insurers to cover losses. Firm lawyers also have what she termed a "smorgasbord" of cases involving insurance coverage issues such as cybersecurity breaches and directors and officers liability.

Indeed, on Jan. 5 - Cohen Ziffer's first day of business - managing partner Frenchman argued on behalf of New Jersey Transit before the Supreme Court of New Jersey. At issue: hundreds of millions of dollars in water damages to the public transportation system's property due to Superstorm Sandy.

The team already won at the trial and appellate level. Now, Frenchman wants the state high court to affirm that a $100 million flood sublimit is inapplicable, and that NJ Transit is entitled to the full $400 million policy payout.

In addition to Cohen and Frenchman, the firm's other name partners are Adam Ziffer and Keith McKenna. All the firm lawyers joined from McKool Smith, with the exception of counsel R. Tali Epstein, who previously worked at Kasowitz Benson Torres.

Cohen describes the firm lawyers as "hard-charging, intense and trial-focused," but also dedicated to fostering a culture where "everyone is rowing in the same direction."

"I haven't been this excited in a long time," she said.