DIANE SAWYER (ABC NEWS)(OC): And finally, the woman being called the happiest woman in America, despite the stress of juggling a career and family. So, what about her life keeps her happy, and can anyone get it? Here's ABC's Sharyn Alfonsi.
SHARYN ALFONSI (ABC NEWS)(VO): They came out of college ready to take on the world. But today, these boomer women are juggling families and work and facing this killer statistic.
SHARYN ALFONSI (ABC NEWS)(VO): They'll earn an estimated three quarters of a million dollars less over their careers than men their age. The result?
GAIL SHEEHY (USA TODAY "YOUR LIFE" COLUMNIST): This generation of women in mid-life has lower wellbeing than any other generation.
SHARYN ALFONSI (ABC NEWS)(OC): Than any other generation?
GAIL SHEEHY (USA TODAY "YOUR LIFE" COLUMNIST): Yes. And this generation is more distressed and stressed.
SHARYN ALFONSI (ABC NEWS)(VO): So, why is Mary Claire Orenic, a working mom, still smiling? Well, she's figured it out. Researchers working with "USA Today" surveyed hundreds of thousands of women and came up with a list of specific things they say boost their happiness. Mary Claire embodies most them. Today, we'll pull back the layers of her work life to learn how to improve ours. First off, at age 50, Mary Claire is a senior manager at her company and she's not slowing down.
MARY CLAIRE ORENIC (HAPPY WOMAN): I need that fulfillment. I've always worked. In fact, I've never worked 40 hours. I don't - think I'll do that when I retire.
SHARYN ALFONSI (ABC NEWS)(VO): Pollsters found the happiest women are still working full time. But on this day, Mary Claire leaves at 3:00 to take her son for a college visit. She told her bosses she works best with a flexible schedule and they allowed it.
SHARYN ALFONSI (ABC NEWS)(VO): Flexibility contributes to happiness in the workplace more than any other benefit, more than onsite child care, job sharing, or even a long sabbatical.
SHARYN ALFONSI (ABC NEWS)(VO): Another secret to happiness? A good friend. People who have a best friend at work are seven times more likely to be engaged during the day. And don't underestimate the power of your commute, either. Researchers found for every ten minutes you're in the car, your happiness goes down a notch. Mary Claire works from home twice a week.
MARY CLAIRE ORENIC (HAPPY WOMAN): To drive an hour and drive home another hour, I've lost two hours of productivity.
SHARYN ALFONSI (ABC NEWS)(VO): And lost family time, a priority for so many women trying to make work, work. Sharyn Alfonsi, ABC News, New York.