Elizabeth Edwards, advocate for changes in the health care system

A family friend says Elizabeth Edwards, the estranged wife of former Democratic presidential candidate John Edwards, has died Tuesday, according to a friend who spoke on the condition of anonymity because the family had not announced her death.

The family had issued a statement Monday that said doctors have told Edwards that further treatment for her cancer would be unproductive. She spent her last days at home in the state of North Carolina with family and friends gathered.

Elizabeth Edwards over the past six years has seen her husband's presidential ambitions thwarted, retreated from public life as their marriage disintegrated over his affair, then emerged to advocate for changes in the country's health care system, all while grappling with her own illness.

"The days of our lives, for all of us, are numbered," Edwards wrote to supporters on Facebook on Monday. "We know that. And yes, there are certainly times when we aren't able to muster as much strength and patience as we would like. It's called being human. But I have found that in the simple act of living with hope, and in the daily effort to have a positive impact in the world, the days I do have are made all the more meaningful and precious. And for that I am grateful."

Edwards' estranged husband, former presidential candidate John Edwards, and their three children were at her side at the Chapel Hill home, the friend reported. In January, Edwards separated from her husband of 30 years after he admitted to an extramarital affair and fathering a child with a campaign videographer. Her sister, brother, nieces, nephews, former campaign advisers and other friends were also there.

Edwards has focused on reforming the country's system of providing health care toward a single-payer process designed to serve all.

She has often wondered aloud about the plight of those who faced the same of kind of physical struggle, but without her personal wealth. Captivated by stories of those who could not afford health care coverage, Edwards has passionately retold them at roundtable discussions, in writings on the Web and on Capitol Hill.

"What I'm really glad about is that I still have a seat at the table to talk about health care — that I have the strength to do it and that I also have a seat at the table," Edwards said at event in October 2008.

Edwards has shared with the public the most intimate struggles of her illness and the efforts to assure her children about their mother's future.

She continued that public face on Monday.

"It isn't possible to put into words the love and gratitude I feel towards everyone who has and continues to support and inspire me every day. To you I simply say: you know," Edwards, a popular figure among Democratic activists, wrote on the Facebook post.

The John Kerry-John Edwards ticket lost to incumbent President George W. Bush. John Edwards launched a second bid for the White House in 2007. The Edwardses decided to continue the campaign after doctors told Elizabeth that her cancer had spread, but he lost the nomination to Barack Obama.

Edwards was more than a political spouse. She was chief adviser and strategist to her husband's campaigns for the Senate and later for the presidency.

The Edwardses met in law school. Daughter Cate has followed her parents into a career in law while son Wade was killed in a traffic accident when he was 16. Elizabeth Edwards had two more children later, giving birth to Emma Claire at age 48 and Jack at 50.

Elizabeth Edwards also allowed outsiders into her recovery from her son's death, in her 2006 memoir.