Erin Callan Montella, on Florida’s Sanibel Island with her 14-month-old daughter, Maggie, the child she “waited so long to have.” (Erin Callan Montella/Erin Callan Montella)

After 12 years at Lehman Brothers, Erin Callan Montella landed in the executive suite at exactly the wrong time.

Her promotion in 2007 to chief financial officer of the large New York investment bank instantly made her one of the most powerful women on Wall Street. But it came just months before investors began to question Lehman’s exposure to subprime mortgages. She would hold the job less than a year.

In her new memoir, “Full Circle: A Memoir of Leaning In Too Far and the Journey Back,” Montella gives a peek into what it took to climb the ranks of the more-than-100-year-old bank.

Montella also provides insight into the male-dominated New York financial world. Montella often found her fashion choices the center of conversation. Once, she said, her boss, then-Lehman chief executive Dick Fuld, told her that “I had a tendency to be too hard on the other, all-male, members of the Lehman executive committee. My interrogatory style could be off-putting and challenging.” Another time, Joe Gregory, another high-ranking Lehman executive, mentioned that Montella was the only one in executive committee meetings “whose legs are showing.”

In the years since Montella left Lehman Brothers, it’s not clear that much has changed on Wall Street. Women account for just 2 percent of financial industry CEOs, according to Catalyst, a nonprofit group. They hold about 29 percent of executive or senior-level positions in the industry.

A former tax lawyer, Montella, now 50, joined Lehman in 1995 and quickly rose to head of the bank’s hedge fund division. Lehman’s president, Gregory, was leading a company-wide effort to improve Lehman’s track record on the promotion of women and minorities, and he had taken notice. Montella was picked for the company’s top finance job in December 2007.

She resigned in late 2008 after Lehman stunned Wall Street by announcing that it had lost nearly $3 billion in a single quarter. It would go on to file the largest corporate bankruptcy in U.S. history.

This conversation has been edited for length and clarity.

Were you immediately aware after being named CFO that you had become one of the most powerful women on Wall Street?

It’s not like it happens overnight. I went there in 1995 and worked very, very hard. I worked too hard.

I put too much time and energy into work and things started to get unbalanced. For me, it was easier to put more and more energy into work, where the rewards were clear, rather than in my personal life, where the rewards were less clear.

There must have been a sense of pride, too.

I don’t want to paint a tainted picture because I had a wonderful career, and I am proud of it. It will always be part of me and who I am.

Why aren’t more women in the finance industry?

The financial industry is just not an appealing work environment period since the crisis.

There is a perception that it is a male-dominated environment, and there is propaganda that tries to enforce that notion. It’s circular. You have to be a bit unconventional to want to go there [as a woman].

Is there a glass ceiling in Wall Street?

I wouldn’t use that terminology. Women still face the fundamental challenge of the work-life balance.

Would I have been able to manage all of this [family life] and still have achieved a similar level of success? That is the big question, and that is an open question.

There are lots of things I could have done differently. I used to work a couple of hours on Sunday, then it turned into all weekend. I was working all of those hours and not getting much out of it.

I am not suggesting you can be a corporate executive and work 40 hours a week, but maybe you don’t have to work 100 hours a week.

The big lesson I am trying to communicate with my story is you can take it too far. You can have a great career and make it the center of your universe. That’s what it was for me and did not lead to a happy outcome.

And it wasn’t just because I was the CFO of Lehman at the wrong moment.

Did you ever feel conscious of being the only woman in a meeting during your time at Lehman? Can you describe that experience?

Most of the time, I was not conscious of being the only woman in any of the settings I was in because it was just a consistent fact. You just stopped noticing it unless something happened to draw special attention to my gender, and most of the time that was not the case.

I have always understood that being a woman on Wall Street cut two ways. There was a real positive to being unique with a different style. That part of the equation is not discussed often, but it shouldn’t be dismissed. There’s a lot of discussion of the negative consequences that are all too familiar.

On the whole, I think my gender translated through my personality and helped make me effective. I got over being the only woman in the beginning of my career when I was a corporate tax lawyer. I think because I didn’t pay a lot of attention to it, most of the time, the people around me were comfortable, too.

What was the bigger challenge for you as Lehman CFO — being a woman or being inexperienced?

The bigger challenge as CFO was unquestionably being inexperienced in the CFO role at a daunting time with a consequential lack of standing and influence. I was absolutely qualified for the job through my prior work experience. The combination of a legal background and investment banking experience with financial institutions, in addition to my track record running a number of successful businesses at Lehman, was unique. I don’t see my gender having played into any of what happened in a meaningful way.

The fact that I was three months into the job when Bear Sterns nearly collapsed really says it all. I think most of my instincts were right about selling assets quickly and trying to address souring investor sentiment, but I didn’t have the decades of experience in the role that the rest of the management team had. If I had an opportunity to grow in the CFO job before the crisis became full-blown, I think my ability to influence events would have been different. There just wasn’t enough time to work with. I was a rookie CFO, and the veterans were calling the shots.

Would you consider going back to Wall Street now, perhaps start your own firm?

I would not, for several reasons. The most important one being that I have a 14-month-old daughter, Maggie. I have waited so long to have a child that I want to be committed to her as a mother, and I am fully committed to my husband and the three of us as a family.

We have dramatically adjusted our lifestyle and simplified our life so we can spend all our time together. Don’t get me wrong, I recognize that this is not balance. Putting 100 percent of yourself into your career for 20 years, then putting 100 percent of yourself into your husband and family after that is not some new definition of balance that I ascribe to. I don’t advocate this approach. But it is my story. And I feel fortunate I have had this chance to experience both realms.