WEST JORDAN — When she was born, a gallon of gasoline was 23 cents, the Boston Red Sox had won the World Series and a new home would sell for about $2,200.

A lot has changed in 100 years, and, even though it hasn't all been easy, Frances "Fran" Allen is still smiling.

"I always choose to be happy," the centenarian said at a birthday celebration held Saturday in her honor at the Vista Montana town houses where she lives.

There's no secret to a long life, she said, other than that.

"It's God's choice whether I live or die," Allen said, adding that she's a firm believer in being nice and doing good things. "I always think there must be something I'm supposed to do to have been here this long."

Though, her family says she's been busy her whole life — doing things for other people.

Allen's youngest great-grandson just turned 2, yet, he's already got a fairly large hand-knitted afghan with his name on it for a high school graduation present. She's done that for all of her eight grandchildren and nearly 20 great-grandchildren. They're folded, labeled and ready to be gifted when the kids come of age.

And each of them know that "Nana" made it special, just for them.

"I feel like they should have something meaningful," Allen said. "There's not a lot of people who do that stuff anymore. And I just love them."

The 100-year-old's eyesight is keen and her hands are nimble, and she says that as long as she's able, she'll work for the benefit of others, creating mementos and whatever she can to help people know they are loved. Allen also crochets baby blankets and sews custom-designed cross-stitch. She loves to do jigsaw puzzles, and she is never without a book to read and said that sometimes she reads into the morning hours without even realizing it.

She tries to eat healthly and exercises daily. And, she still has a valid Utah driver's license.

Five days before Christmas, she fell down some stairs and got 17 staples to close a gash in her head. But Allen still hosted all her grandkids and great-grandkids at an annual Christmas Eve breakfast at her house.

"She's taught us all a love of family, about traditions and remembering people, and about service," said Caleb Lindquist, 20, a great-grandson who lives in Herriman. He said Allen is "positive about everything."

"Even if things are hard, she's always got a smile on her face," he said. "Nothing slows her down."

Allen followed an older brother into the Navy and served as a pharmacist mate during World War II, under the direction of medical officers. She never left the country but was stationed all over the East Coast, and, ultimately, at a receiving depot in Boston helping soldiers coming home from war.

"I'm proud of my time in the Navy," she said. "I'm proud that I've lived this long."

She credits a "wonderful family" — a family, she said, "that just loves each other."

One wouldn't guess it by her countenance, but Allen hasn't had an easy life.

Her father died when she was 10 years old and she grew up on a farm in the Midwest, partly during the Great Depression. She's been through divorce, largely raised three kids alone, and has watched many friends and family members, including two husbands, pass away.

"She has a lot of built-in coping skills," said Allen's daughter, Jo Lavin, of Riverton. "She's always doing something for someone else."

Lavin doesn't worry much about her mom, who lives pretty independently, except for her oldest son who lives with her. She said her mom makes friends easily and never forgets things about people.

"Mom was always there for us," Lavin said.

"I hope I can follow in her footsteps," said Jim Call, Allen's youngest, who lives in Oregon and came to Utah for his mom's party.

Since burying her second husband, Allen has said she wants to live to be 104.

There isn't anyone who knows her who doesn't believe she'll make it to at least that.