Image credit: Courtesy Mary Claire Orenic

Mary Claire Orenic – declared “the happiest woman in America” by USA Today – has it all.

The 50-year-old California resident is a senior manager at Siemens Healthcare, a global company that allows her to work from home at least two days a week. Her only son, Christopher, is headed to college and her husband is a successful optometrist. On top of all that, Orenic is in perfect health.

“I’m happy,” she told ABC News. “It’s a big part of who I am, how I get up every day and my life with my husband and my son.”

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According to experts, Orenic is the model of a high level of well-being for women in the 45- to 55-year-old age group, the largest demographic in the United States today.

For its series on well-being this week, USA Today asked Healthways to identify contributors to a good well-being in women.

Besides a healthy work-life balance, which ABC News discussed Tuesday, Healthways researchers found that children combined with diet and exercise were tied to a woman’s happiness.

Here are 5 tips to get you eating better and working out.

Pollsters said that women who had fewer children and gave birth to their last child between the ages of 27 and 36 were happier than those who waited to have kids.

Orenic was 33 when she told her husband she was ready to have a baby. She had traveled the country and advanced her career by then and her husband had completed his residency. They agreed to have just one child. For baby Christopher’s first year, Orenic’s husband was a part-time, stay-at-home dad while she worked to keep her six-figure salary.

Gail Sheehy, a journalist and author of the 1970s’ best-seller “Passages,” said that a parent would be “limited” if at 50 years old, he or she still had a 10- or 15-year-old to raise.

“Especially if you also have care-giving responsibilities for parents or in-laws,” she said. “If you had your last child by 36, when you’re 50, he or she is on their way out and you can do ballroom dancing with your husband.”

Orenic told USA Today that while she would miss her son when he left for school, she was proud of how he’d matured into adulthood. “That accounts for a lot of my optimism about the next five years,” she said.

Despite her 40- to 60-hour workweeks, Orenic said she still made time to work out every day and maintained a healthy diet.

“Being inside all day, I can’t wait to get outside,” she said.

Orenic plays volleyball with her son; shoots hoops with her husband on the weekends; and takes walks with a neighborhood pal in the mornings to vent and decompress.

Researchers at California State University found that 10 minutes of fast walking boosted energy for at least two hours.

“I walk as much as I can,” said Orenic, who lives close to Manhattan Beach. “We probably do three to four miles on a walk. … Whenever I can during the week, but it’s primarily on the weekends, I get on the elliptical, I do weights, I play basketball and I take a hip-hop dance class as well, which I love.”

At 115 pounds, the 5-foot-6-inch Orenic said she eats five small meals a day to keep her energy up. Her husband does the supermarket shopping and the cooking every day, even making her lunch when she’s working from home.

According to Healthways’ data, three of four women age 45 to 55 who were polled said they didn’t get enough energy during the day and one in four were on an antidepressant.

Orenic said family, friends and her well-being helped keep her happy.

“I like him,” she said of her husband, Chris. “If he wasn’t my husband, I’d hang out with him. I’d rather be with him than anybody else. … I have friends from 30 years ago and women I grew up with, people that I’ve met along the way that I’ve kept up with and new friends here in Manhattan Beach.”

But Orenic said she didn’t take her good fortune for granted.

“I think I’m pretty darn lucky,” she said. I” don’t really have anything to complain about.”