Photo: Shutterstock.

I used to think female leaders at major law firms were unusual, almost shocking—like seeing a gazelle gliding across Times Square.

Thankfully, they've become less exotic in the last several years. At a few firms, women have held the top spot long enough to be fixtures, such as Akin Gump Strauss Hauer & Feld's Kim Koopersmith and Morgan, Lewis & Bockius' Jami Wintz McKeon. And this year, more women are joining their ranks, including at Ropes & Gray; Kelley Drye & Warren; Boies Schiller Flexner; and Jenner & Block.

It's not quite a critical mass, but change is in the air. So if women are increasingly in charge, shouldn't the pace of progress for gender equality finally kick into high gear?

Expectations are high. Probably too high. Female managers do not contribute to greater gender equality, particularly in earnings, according to a study in the European Sociological Review that analyzed data from nine countries. The bottom line: Female managers are cogs in the machine, not agents of change.

Of course, it's tempting to think that women at the helm will make a difference. The study says we assume female leaders are more empathetic because they've experienced gender discrimination and understand work/life tensions. Plus, female managers "challenge stereotypes about women's ambition and capability."

Women who reach those lofty positions have already beaten the odds, and they have more than enough on their plates as firm leaders, yet we expect them to deliver more than men in the same situation.

Being a boss is fraught, female leaders say. "We are all under pressure to perform," Katya Jestin, Jenner & Block's new co-managing partner, says. "For women leaders, the pressures are greater and more intense."

Female leaders are highly conscious of how others perceive their leadership style, including their likability.

"There are attributes of my style that are likely consistent with gender stereotypes," Julie Jones, chair of Ropes & Gray, says, including promoting teamwork and being a good listener. "But some of my style is not consistent with stereotypes. I can be tough, especially when it comes to performance."

Undoubtedly, female chieftains are a tough, select bunch, so how much do they relate to the women struggling in the ranks? And do they face pressure to deliver for other women?

Candace Beinecke, the grand dame of this crowd, says she didn't feel that pressure when she served as chair of Hughes Hubbard & Reed from 1999 to 2016.

"Hughes Hubbard had a long history of providing opportunities for women, and I don't believe the women at our firm had that in mind for my role," she says.

One of the first female leaders of a major firm, Beinecke says her role was more indirect: "I did hear from many how inspiring it was to see a woman in this leadership position and how helpful it was to have the role model." That said, she adds, "knowing that my career depended on people taking a chance on me when it was not expected made me committed to encouraging that same approach by others."

Some of the younger female leaders take a more proactive approach. "I try to see every decision through the lens of diversity and inclusion, and to help in my small way bridge the opportunity gaps that exist," says Jestin, a former federal prosecutor and parent of three children.

"Women do talk to me about their careers," Natasha Harrison, Boies Schiller's new co-managing partner, says. A British citizen of Greek origin who was the first in her family to attend university, the London-based Harrison says, "I see it all as about challenging the status quo. As a diverse creature myself in terms of gender and background, I feel strongly about this issue." Diversity, Harrison stresses, includes "all types," including economic and social status.

But with all the challenges that Harrison faces (Boies has had a series of partner defections this year), does she need this extra burden to promote equality? Isn't this an unfair expectation that's put upon women?

"I don't think of it as pressure, but rather, opportunity and privilege," she says.

Contact Vivia Chen at [email protected]. On Twitter: @lawcareerist.