Elizabeth Edwards: Lawyer who acted as political adviser to her husband John before revelations of his infidelity

In a world which increasingly sees things in black and white, the life of Elizabeth Edwards was a reminder that politics, like life itself, exists in shades of grey. In the early stages of her husband John's political career she was his greatest asset, the exemplary political wife.

She was his key adviser, unafraid to publicly voice differing opinions to his on issues like the Iraq War and gay marriage, helping to reduce the impact his own stands might have had. She was already a public figure of inspirational sympathy; a successful lawyer and a mother who had survived the tragic loss of a teenage son to start a second family even as her husband embarked on his political career.

Then, on 3 November 2004, immediately after her husband and the presidential candidate, John Kerry, conceded defeat to the incumbent Republican ticket of George Bush and Dick Cheney, she was at Massachusetts General Hospital for the first treatment of her just-diagnosed breast cancer. Her 2006 book, Saving Graces: Finding Solace and Strength from Friends and Strangers, detailed her battles against tragedy and disease. Her status as an American icon of survival was only intensified when her cancer returned, yet she continued to work on her husband's run for the 2008 Democratic presidential nomination. Edwards withdrew after finishing behind both Hillary Clinton and Barack Obama in the first four contests, including South Carolina, which he had been expected to win.

Then, in August 2008, came the revelation of her husband's affair – which produced a child – with Rielle Hunter, the woman hired to produce his campaign videos.

There were intriguing parallels between 2008's three Democratic contenders. Like Bill and Hillary Clinton, the Edwardses met in law school; and as with Michelle Obama, who met Barack when he interned at her law firm, she was slightly older than her husband. Edwards often called herself "the anti-Barbie", a reference to her husband's characterisation as a good-looking but empty "Ken doll". A White House official went further and dubbed him "the Breck girl", after the glossy model in the US shampoo ads.

When, in March 2007, her cancer returned, and spread, her decision to continue campaigning saw some accuse her and her husband of cynically playing on her illness, particularly in her strong support of a national health care plan. After the right-wing pundit Ann Coulter wished for John Edwards to be killed by terrorists, Elizabeth ambushed her on a television call-in programme; her calm insistence that she be allowed to preserve her dignity reduced Coulter to a caricature of indignation.

Yet by this time, Edwards was already hiding the secret of her husband's affair. Two recent books have presented warts-and-all pictures of the Edwards' marriage. The Politician, by Andrew Young, the aide John Edwards originally arranged to claim paternity of Hunter's child, highlights the cynicism of her silence about the affair, while Game Change, by John Heilemann and Mark Halperin, claimed with disingenuous hyperbole that aides felt that "there was no one on the national stage for whom the disparity between public image and private reality was vaster or more disturbing." It portrays her as demanding, controlling, and derisive of her husband's "redneck" background and lack of intellect.

Mary Elizabeth Anania was born in 1949 in Jacksonville, Florida. Her father was a US Navy pilot, her mother the daughter of a Navy pilot and the widow of another. The family moved often throughout her childhood, which included a stay in Japan; she trans-ferred from Mary Washington College in Virginia to the University of North Carolina when her father was assigned to teach there. She graduated with a degree in English, but while in graduate studies switched, and met John Edwards while getting her law degree. The couple married the day after taking the North Carolina bar exam, and while he established a hugely profitable career as a tort lawyer, she worked for the states' attorney's office, and then in bankruptcy law, using her maiden name.

They lived a comfortable life in the state capital, Raleigh, until 1996, when their 16-year-old son, Wade, was killed in a car accident, three weeks after he had received an award as a finalist in a national essay contest at the White House from Hillary Clinton. In her book, Edwards detailed her grief, which included daily visits and conversations at her son's grave, and how it changed their lives. The couple started a foundation in their son's name.

Edwards took fertility treatments that led to two more children, and as she formally adopted her husband's surname he began a campaign that ended in his winning a US Senate seat in a huge upset over the right-wing Republican Jesse Helms's protégé, Lauch Faircloth. Rather than seek re-election in 2004, Edwards ran for the Democratic nomination, and was taken on by the eventual winner Kerry as his running mate.

His affair with Hunter began in 2006, as he started his campaign for the 2008 nomination. In her 2009 book, Resilience: Reflections on the Burdens and Gifts of Facing Life's Adversities, Elizabeth was unstinting in detailing the progress of her husband's gradual confession. She wrote: "Just as I don't want cancer to take over my life, I don't want this indiscretion, however long in duration, to take over my life either." But when Edwards confessed paternity just before the publication of The Politician in January, they parted. A year's separation is a requirement for divorce in North Carolina. She died at home, having recently ceased treatment after the cancer had spread to her liver.

Mary Elizabeth Anania, lawyer and political adviser: born Jacksonville, Florida 3 July 1949; married 1977 John Edwards (two daughters, one son, one son deceased); died Chapel Hill, North Carolina 7 December 2010.