Cindy McCain has never been one to bask in the spotlight. She takes the stage a little reluctantly, speaks softly enough that she sometimes buries her best lines, and has a mild, low-key demeanor.

On the campaign trail, she seems content to play third fiddle to husband John McCain and his running mate, Sarah Palin, projecting the image of a traditional mother and wife.

But beyond the perfect, platinum blond political wife with ice blue eyes and Escada suits, there is another Cindy McCain -- a more daring woman who likes race car driving and earned her pilot's license without telling her husband.

"She is really both of those people," said Paul Alexander, a biographer of John McCain who also has spent time with Cindy McCain.

As a volunteer for charities, she dresses in jeans, T-shirts and hiking boots and travels to the least-glamorous parts of the globe: Vietnam, Thailand, Cambodia, Kosovo, Rwanda and Georgia this year alone.

"She has her own mission," said Oakland County Clerk Ruth Johnson, a Republican. "She's very tenacious and compassionate. ... She'll inspire more people to get involved."

In a story people love to tell about her, McCain, while visiting an orphanage in Bangladesh in 1991, argued with officials to take two sick girls home with her. Her husband knew she was returning with the girls, but he didn't know she planned to adopt one of them. (The other was adopted by a former John McCain aide.)

This is your new daughter, Cindy McCain told her husband when he met her at her plane in Arizona.

She said John McCain didn't skip a beat, welcoming the baby into the family. And that's how Bridget McCain became the youngest of the McCain children.

"She swept her out of an orphanage," said former U.S. Rep. Joe Schwarz, a Battle Creek Republican who has traveled with the McCains. "That's the kind of person she is."

'She is no shrinking violet'

She's also an heiress estimated to be worth more than $100 million and a successful businesswoman who chairs the family Anheuser-Busch beer distributorship.

She's a strong-minded, independent, outdoors-loving woman with her own opinions, Alexander said.

McCain demonstrated her independence earlier this month when she disagreed with Palin on abortion, saying it should be allowed in cases of rape or incest.

"She's not just another pretty face," said Holly Hughes, cochair of the McCain campaign in Michigan. "She is no shrinking violet."

Hughes, who has traveled with the McCains through two elections, said she considers Cindy McCain a campaign asset for the stability she brings her husband when she's on the trail.

"They're very gentle together, and you occasionally see them hold hands or see a kiss on the forehead," she said.

Schwarz said Cindy McCain is a mother before anything else. He recalls campaigning with her in Michigan in 2000 and hearing her talking with daughter Meghan McCain in Arizona, who had done something her mother had asked her not to do.

"Cindy said: 'That is unacceptable, and you are grounded!' " he said. "She grounded her daughter by phone."

McCain says she's her husband's best critic.

"I am the one person he can trust," she told "Nightline" last year. "I'm the one person who will tell him in the end exactly what I think and what's wrong. You know, he needs to hear that sometimes."

McCain has said that as first lady, she would focus on adoption, encouraging Americans to volunteer, and addiction -- all things she has experienced personally.

In 1994, she admitted publicly -- as some news media were about to air a story about it -- that she was addicted from 1989 to 1992 to the painkillers Percocet and Vicodin after back surgery. Her husband didn't know.

She stole pills from a charity -- which she founded -- that delivered medical supplies overseas. She got a doctor there to write fake prescriptions for her in the names of employees.

Although she has said she quit when her parents confronted her in 1992, a former charity worker blew the whistle to the Drug Enforcement Administration, which investigated.

She was never charged, instead reaching an agreement with federal authorities to pay restitution and do community service.

She is open about her addiction.

"It is a national problem, particularly for women," she said earlier this year. "I try to talk about it as much as possible because I don't want anyone else to wind up in the shoes I did at the time."

'I was in love'

John McCain was married when he met Cindy Hensley at a cocktail party in Hawaii in 1979, while she was on vacation with her parents.

"She was lovely, intelligent and charming," he wrote in his political biography, "Worth the Fighting For." "I monopolized her attention the entire time. ... I persuaded her to join me for drinks at the Royal Hawaiian Hotel. By the evening's end, I was in love."

In a separate interview, Cindy McCain said: "I had dated men my own age, but John was just intriguing, so well-read and well-spoken and interesting. I was spellbound by him."

The two began dating. His marriage already was faltering. Divorce records cited at the time say John McCain lived in the same house with his wife until they formally separated in January 1980.

He filed for divorce in February. It was granted in April, and he married Cindy McCain in May.

She's 54; he's 72. They both lied about their ages when they met. (He lied downward; she lied upward.) The couple has been married 28 years.

Besides Bridget McCain and Meghan McCain, who just wrote a children's book about her father, the couple has two sons: Jimmy McCain, who returned home earlier this year from a stint as a Marine in Iraq, and Jack McCain, a senior at the U.S. Naval Academy.

John McCain has three children from his previous marriage. All seven McCain children were onstage with their dad at the Republican National Convention.

A professional, a mother

Cindy McCain is a director of Operation Smile, which offers free surgery to kids in foreign countries with cleft palates and other deformities; a trustee of HALO Trust, which removes land mines, and a board member on leave from CARE, an international charity.

Until it closed in 1995, she led more than 55 missions overseas for American Medical Voluntary Team, a charity she started in 1988.

The McCains keep their finances separate under a prenuptial agreement.

As chair of Hensley & Co., the beer distributor she inherited from her late father, Cindy McCain conducts business by video, biographer Alexander said.

She was born in Phoenix and raised her children in the house where she grew up. She has lived in Washington only a year.

McCain, a state rodeo queen at 14, has a graduate degree in special education and an undergraduate degree from the University of Southern California, where she was a cheerleader. After graduation, she taught disabled students in Phoenix for a year.

On daughter Meghan McCain's blog, she is just mom: petting family dogs Lucy and Coco, fishing foil out of a drawer at the family ranch in Sedona, Ariz., as she helps her husband prepare a barbecue, wearing funny eyeball glasses.

But Cindy McCain was ambivalent about her husband's run for the presidency.

When he first approached her about running for president again, "I said 'Hell, no.' ... I just didn't think I had wide enough shoulders for this again," she said last fall.

McCain said she changed her mind because her husband was the only person she trusted to be in charge of the country while her sons were in the military.

She discovered the ugliness of presidential politicking in the 2000 presidential campaign, when Republican rivals attacked her husband in North Carolina by circulating rumors that Bridget McCain was John McCain's love child. She said she was appalled.

This has been a far smoother campaign for her, so far. But there have been stumbles.

Cindy McCain always has said she's an only child. But Kathleen Hensley Portalski of Phoenix, her father's child by an earlier marriage, surfaced this summer and said she was bothered by McCain's failure to mention her.

"I felt like a nonperson," she told National Public Radio, adding that she planned to vote for Barack Obama. McCain also has another half-sister from her mother's first marriage.

In August, a flap arose over the number of houses the McCains own, which her husband wasn't sure about. That may be because most are in Cindy McCain's name or the children's names, or owned by family trusts.

According to real estate documents posted on PolitiFact.com, the correct answer is eight properties: a $4.6-million, 6,600-square-foot condo in Phoenix that is the main family home; the senator's condo in Arlington, Va., just outside Washington; a $1.6-million ranch near Sedona, Ariz.; three condos near San Diego, and two more in Phoenix, including one for Meghan McCain.

'Friendly and down-to-earth'

Myra Gutin, a communications professor at Rider University in New Jersey and an expert on first ladies, said Cindy McCain would enter the White House with her own résumé and concerns but wouldn't get involved in policy.

"I think people would be comfortable with Cindy," Gutin said.

Gutin said mistakes and missteps make the candidates seem more earthly.

"Potential first ladies are another element in a voter's decision," she said. "They give a clue to a candidate's character. ... You like to think they have solid marriages, happy children and basically have been good citizens."

Imperfect children or problems like McCain's drug addiction simply make them more human, as long as they are forthright about them, she said.

Gutin said women pay more attention to the candidates' wives than men do, and in this election, women's votes are critical.

"She's friendly and down-to-earth," said Goldie Feinberg, 80, of West Bloomfield, a McCain volunteer and former Hillary Clinton supporter