Artist Marilee Shapiro Asher, who turns 103 on Tuesday, is still making art at her apartment in her retirement home in Washington. (Sarah L. Voisin/The Washington Post)

Everyone asks the centenarians: “What’s your secret?”

The answer is pretty simple: work.

In her sun-drenched studio at a Washington retirement home, Marilee Shapiro Asher has a hot wax knife, a handsaw, a hacksaw, plaster molds and bronze pieces at her worktable. There are also prints everywhere, because she’s on a photography binge, and she’s finally experimenting with color.

“I’ve always been afraid of color,” she said. “So I’m working on that right now.”

Her digital prints are playful, abstract takes on soap bubbles, flowers and shadows. Over the years, she has worked in ceramics, bronze, paper and steel. Her last show was in 2012 at Gallery Plan B, which closed on 14th Street NW a few months ago.

Mabel Sawhill, center, a 102-year-old caterer, talks with guests during a lunch at the Bethesda Women's Club. (Paula Eve/Paula Eve)

A short drive away, in Silver Spring, Mabel Sawhill put the finishing touches on a luncheon she was serving to 50 members of the Bethesda Women’s Club — turkey, mashed potatoes, kale salad, vegetables and her famous sticky buns. But she also was fretting about the funeral of a 97-year-old family friend she was attending afterward.

“They were going to just serve cake and coffee, and that’s just not right,” she explained. So at 3 a.m., she made sandwiches. A couple hundred little ones.

The caterer is 102 years old. And Marilee, who often uses a walker but is otherwise in good health, turns 103 Tuesday. They’re both lively and engaged, voracious consumers of life. And they’re still working.

The number of American centenarians is growing — it has nearly doubled in the past 30 years, to nearly 55,000 today. People are living longer. Longevity isn’t the challenge it once was. But living fully in that second century still is.

So that’s why people such as Marilee and Mabel are so fascinating. (There’s something else about centenarians — they ascend to single-name status and insist on it.)

Mabel, who was born in 1913, when Woodrow Wilson was president, launched her catering business when she was — wait for it — 70.

Marilee Shapiro Asher holds the wax model for casting for her piece “Guard Dog Big.” She has been a working artist all her life and remains active. (Sarah L. Voisin/The Washington Post)

She had been doing it on the side for decades while working as an administrative assistant at the Navy’s Bureau of Medicine and Surgery. She was a schoolteacher in her native Iowa until World War II, when she decided that “everybody was doing their part, and I thought I should do something for my country.” So she moved to Silver Spring and took that government job.

In 1983, Mabel retired from her federal desk job and started catering full time. She does about 100 events a year — weddings, funerals, social clubs, a summer church camp in West Virginia. She does her own grocery shopping and did her own driving until last year. She accepts some driving help now, calling it an efficiency measure.

She has never needed eyeglasses and was able to read some small print that I had to get my specs out to see.

There is a small group of people who have had Mabel cater both their weddings and their 50th wedding anniversaries. She insisted on catering her own 100th birthday party. They expected 450 people. Seven hundred showed up.

“When we realized that we had about 700 people, I ran out and started cutting the meatballs in half,” she remembered.

She loves shoes and still treasures the black-and-yellow polka-dot pumps she bought years ago at the now-defunct Garfinckel’s department store. She loves sports, putting together a March Madness NCAA basketball bracket every year. Her goal before her 103rd birthday next October is to join a fantasy football league. And she’s a deeply religious member of Wallace Presbyterian Church in College Park who asks God for guidance every day.

Mabel’s version of The Secret?

“I never married,” she said.

But she helped put her deaf brother through Gallaudet University, helped send nieces and nephews to college and raised more than $30,000 for a scholarship fund at Gallaudet.

Marilee, on the other hand, had two husbands and two children. She calls them “the center, the interest, the worry, the pleasure, the ‘raison d’être’ of my life,” in her autobiography, “Dancing in the Wonder.”

Are they her Secret?

“Being selfish” — that’s her key to aging so vivaciously, she told me. “And exercise.”

She’s been doing tai chi every day for decades. And she’s always worked, even when her children were young and other women didn’t work.

“I had to be selfish in order to keep making art,” she said.

Marilee’s daughter once wondered whether it was Geneva — the family housekeeper/cook/nanny — who primarily raised her. But they came to agree that Marilee’s work as an artist was an important part of her daughter’s upbringing, too.

Marilee had her first show in Chicago in 1938, and her work was sold in Washington galleries for decades. She was on staff at American University and spent years as an art therapist at the National Institute of Mental Health.

She never let her art self be suffocated by her Mom self.

In her late 80s, when she began having difficulty moving and working with large, heavy bronze sculptures, Marilee didn’t retire. She found a new medium — digital. She enrolled in a Corcoran class on digital photography at 88. Her classmates were all in their 20s. But she learned to use a computer, to use Photoshop, to create a Web site. All alongside students nearly 70 years younger.

That’s another thing about reaching 100. Marilee and Mabel have outlived just about all their peers.

Mabel’s friends have all asked her to cater their funerals, so she does a lot of those. Last week she told me she had to find a new lawyer because she outlived her old one.

Marilee outlived the last gallery that showed her work. She’s open to finding a new one.

Slowing down? Not for these two.