Barbara Bush, the snowy-haired first lady and mother of a president whose plainspoken manner and utter lack of pretense made her more popular at times than her husband, President George H.W. Bush, died Tuesday, a family spokesman said. She was 92.

Mrs. Bush brought a grandmotherly style to buttoned-down Washington, often appearing in her trademark fake pearl chokers and displaying no vanity about her white hair and wrinkles.

"What you see with me is what you get. I'm not running for president — George Bush is," she said at the 1988 Republican National Convention, where her husband, then vice president, was nominated to succeed Ronald Reagan.

The Bushes, who were married Jan. 6, 1945, had the longest marriage of any presidential couple in American history. And Mrs. Bush was one of only two first ladies who had a child who was elected president. The other was Abigail Adams, wife of John Adams and mother of John Quincy Adams.

"I had the best job in America," she wrote in a 1994 memoir describing her time in the White House. "Every single day was interesting, rewarding, and sometimes just plain fun."

On Sunday, family spokesman Jim McGrath said the former first lady had decided to decline further medical treatment for health problems and focus instead on "comfort care" at home in Houston. She had been in the hospital recently for congestive heart failure and chronic obstructive pulmonary disease. In 2009, she had heart valve replacement surgery, and she had a long history of treatment for Graves' disease, a thyroid condition.

"My dear mother has passed on at age 92. Laura, Barbara, Jenna, and I are sad, but our souls are settled because we know hers was," former President George W. Bush said in a statement Tuesday. "Barbara Bush was a fabulous First Lady and a woman unlike any other who brought levity, love, and literacy to millions. To us, she was so much more. Mom kept us on our toes and kept us laughing until the end. I'm a lucky man that Barbara Bush was my mother. Our family will miss her dearly, and we thank you all for your prayers and good wishes."

George H.W. Bush held his wife's hand all day Tuesday and was at her side when she died, according to Jean Becker, chief of staff at George H.W. Bush's office in Houston.

A funeral is planned Saturday at St. Martin's Episcopal Church in Houston, which Mrs. Bush and her husband regularly attended. Mrs. Bush will lie in repose Friday at the church for members of the public who want to pay respects. Saturday's service will be by invitation only, according to the George Bush Presidential Library Foundation.

"Barbara Bush challenged each of us to build a better world by empowering people through literacy. As only one of two women in American history who can be called First Lady and First Mother, she was matriarch of a family that remains as dedicated to public service as it was to politics," said former Secretary of State and White House Chief of Staff James Baker III.

The publisher's daughter and oilman's wife could be caustic in private, but her public image was that of a self-sacrificing, supportive spouse who referred to her husband as her "hero."

In the White House, "you need a friend, someone who loves you, who's going to say, 'You are great,'" Mrs. Bush said in a 1992 television interview.

Her uncoiffed, matronly appearance often provoked jokes that she looked more like the boyish president's mother than his wife. Late-night comedians quipped that her bright white hair and pale features also imparted a resemblance to George Washington.

Eight years after leaving the nation's capital, Mrs. Bush stood with her husband, the 41st president, as their son George W. was sworn in as the 43rd president. They returned four years later when he won a second term. Unlike Mrs. Bush, Abigail Adams did not live to see her son's inauguration. She died in 1818, six years before John Quincy Adams was elected.

Mrs. Bush insisted she did not try to influence her husband's politics.

"I don't fool around with his office," she said, "and he doesn't fool around with my household."

In 1984, her quick wit got her into trouble when she was quoted as referring to Geraldine Ferraro, the Democratic vice presidential nominee, as "that $4 million — I can't say it, but it rhymes with rich."

"It was dumb of me. I shouldn't have said it," Mrs. Bush acknowledged in 1988. "It was not attractive, and I've been very shamed. I apologized to Mrs. Ferraro, and I would apologize again."

Daughter-in-law Laura Bush, wife of George W., said Mrs. Bush was "ferociously tart-tongued."

"She's never shied away from saying what she thinks. ... She's managed to insult nearly all of my friends with one or another perfectly timed acerbic comment," Laura Bush wrote in her 2010 book, "Spoken from the Heart."

In her 1994 autobiography, "Barbara Bush: A Memoir," Mrs. Bush said she did her best to keep her opinions from the public while her husband was in office. But she revealed that she disagreed with him on two issues: She supported legal abortion and opposed the sale of assault weapons.

"I honestly felt, and still feel, the elected person's opinion is the one the public has the right to know," Mrs. Bush wrote.

She also disclosed a bout with depression in the mid-1970s, saying she sometimes feared she would deliberately crash her car. She blamed hormonal changes and stress.

"Night after night, George held me weeping in his arms while I tried to explain my feelings," she wrote. "I almost wonder why he didn't leave me."

She said she snapped out of it in a few months.

Mrs. Bush raised five children: George W., Jeb, Neil, Marvin and Dorothy. A sixth child, 3-year-old daughter Robin, died of leukemia in 1953.