Former first lady Barbara Bush, one of only two women in American history to have been both the wife and the mother of a U.S. president, died in her home in Houston on Tuesday at the age of 92.

She had been in declining health for some time and recently decided not to seek further treatment.

Known for her shock of white hair and trademark pearls, Barbara Bush was quickly branded the nation’s “grandmother in chief” when her husband, President George H.W. Bush, ascended to the White House in 1988. But her matronly appearance and polite disposition concealed a sharp tongue and devilish wit that she later became known for, as she increasingly stepped forward as her husband’s defender during his presidency and a rough-and-tumble reelection campaign that he ultimately lost to Bill Clinton.

While her husband was the linchpin of a multigenerational political dynasty, Bush provided much of the steel in the family. Forgoing a career of her own to take care of her kids and support her spouse’s political ambitions, she once said, “My career was my family.” She was of a generation where women were largely defined by their fathers and whom they married, but as the times changed, so did she, gradually showing more of the strong personality that led her kids to lovingly describe her as “the enforcer.”

Born Barbara Pierce, she was raised in the tony New York City suburb of Rye, the third of four daughters born to Pauline and Marvin Pierce, a prominent magazine publisher whose titles included McCall’s, one of the first publications aimed at women.

Barbara Pierce, the future Barbara Bush, is shown in her graduation photo from Ashley Hall, a finishing school in Charleston, S.C., in 1943. (Photo: AP)

Slideshow: Barbara Bush: A life in pictures >>>

Barbara was 16 and home on vacation from Ashley Hall, a posh South Carolina boarding school, when “the handsomest man I ever saw” approached her at a Christmas dance. George H.W. Bush, who introduced himself as Poppy, was a 17-year-old senior at Phillips Academy in Andover, Mass., and lived in nearby Connecticut. He couldn’t waltz, so the two sat and talked and “haven’t stopped talking since,” she later said. A year and a half later, as George prepared to head off to World War II, they became engaged, and in 1945, when he was on leave from his assignment flying bombing missions over the Pacific, they wed. “I married the first boy I ever kissed,” she said.

Just 19, Barbara dropped out of Smith College and followed her husband on what would become a storied career taking him from the East Coast to West Texas and overseas. She was an eager partner in her husband’s career, which took her to environments far removed from her prim upbringing, like Midland, Texas — an oil town that would become as important in Bush family lore as Kennebunkport, Maine, home of the family’s seaside retreat. Along the way, the couple would raise four sons — George W., Jeb, Neil and Marvin — and a daughter, Dorothy.

But the Bushes also suffered terrible loss. In 1953, just a few months after their son Jeb was born, their second child, Robin, was diagnosed with leukemia — a disease for which there were few treatments at the time. The girl died two months before her fourth birthday, an ordeal that sent 28-year-old Barbara into depression and caused her reddish-brown hair to turn white, something she concealed for years using hair dye.

Struggling to overcome her grief, Barbara relied heavily on her husband and eldest son, George W., until one day when she heard her son tell a friend he couldn’t play because his mother needed him. “That started my cure,” she told her husband’s biographer Jon Meacham. “I realized I was too much of a burden for a little 7-year-old boy to carry.”

Future presidents George H.W. Bush and George W. Bush pose with Barbara Bush in Rye, N.Y., summer 1955. (Photo: Newsmakers/Getty Images)

As her husband began his political ascent, which included a stint in Congress, time as head of the Republican Party, director of the Central Intelligence Agency, ambassador to the United Nations and the U.S. envoy to China, Barbara followed, but stayed mostly behind the scenes, taking care of the family. But she edged more into the spotlight when her husband decided to run for president in 1980, joining him on the road as a trusted companion and his most enthusiastic cheerleader in ways that often conflicted with her image as a docile housewife.

According to the Boston Globe, Barbara once barged into the paper’s New Hampshire bureau ahead of the 1980 primary demanding to know why reporters weren’t covering a press conference her husband was holding downstairs. Like a stern mother, she eventually marched a reporter and editor down to her husband’s event, which they covered.

During the 1984 campaign, she made waves when she slapped back at Geraldine Ferraro, the Democratic vice presidential nominee, for attacking her husband. Asked about her opinion of Ferraro, Bush told reporters, “I can’t say it, but it rhymes with rich.” (Afterward, she called and apologized to Ferraro, saying, “The poet laureate has retired.”)

But as she became more visible in her husband’s career, she became a target for jokes about her appearance. She had stopped dying her hair — joking that she just couldn’t get it that “perfect brown.” That prompted some to say she looked more like her husband’s mother than his wife — an insult friends say she found particularly wounding, though she didn’t let on in public.

On the campaign trail and later as first lady, she made light of the comments about her appearance, once dryly recalling how she saw a photographer frantically waving to “get that lady out the way” because he was trying to take a “beautiful picture” of Bush and his family, only to realize he was talking about her.

At the White House, Barbara Bush initially forged a more traditional role as first lady, embracing pet projects like promoting literacy and downplaying her political profile.

George H.W. Bush and Barbara Bush pose with family as he accepts the Republican nomination for reelection in August 1992. (Photo: Ralf-Finn Hestoft/Corbis via Getty Images)

While she pointedly said she did not see herself as a “co-president” and often tried to steer clear of policy matters, Bush made clear that she had a mind of her own and was willing to express it to her husband. “I tell George what I think and no one else,” she told the Associated Press in 1988.  Her husband, in turn, branded his wife with the nickname “Miss Frank.”

During the 1992 campaign, Bush emerged as one of her husband’s fiercest defenders on the campaign trail. She took on commentators who assailed her husband as a “wimp” and “out of touch” and presented him as a good and decent public servant who had been unfairly maligned by Clinton and other opponents.

For the first time, she also broke with her husband politically. She weighed in on issues like abortion, which she said should be a “personal choice” for women, and gun control, admitting that she was for it, while her husband was not. That year she delivered a primetime speech at the Republican National Convention — a first for any first lady in history in what has since become tradition for both parties.

Though her husband lost, Barbara Bush continued her role as a blunt grandma right into private life and in her kids’ political campaigns, as they tapped her as a greater asset than their father. When her oldest son, George W. Bush, began his ascent up the political ladder, first as governor of Texas and then as the nation’s 43rd president, he often told reporters that he had inherited his “daddy’s eyes” and his “mama’s mouth.”

Bush’s passing brings an end to one of the most epic romances in politics. The couple celebrated their 73rd wedding anniversary in early January. She leaves behind five kids, 14 grandchildren and seven great-grandchildren.

President George W. Bush, first lady Laura Bush, former first lady Barbara Bush and former President George H.W. Bush sit surrounded by family in the Red Room of the White House, Jan. 6, 2005. (Photo: Eric Draper/White House via Getty Images)