Elizabeth Edwards, who said the affair deeply shattered her self-confidence, was careful not to use the word "affair" in the interview to describe her husband's relationship with Hunter.
She said the video producer who worked for her husband's campaign seduced her husbands with four words, "You are so hot."
"If you asked me to wager this house we were building whether my husband would've responded to the come-on 'You are so hot,' I would've responded, no," she told Winfrey. "And I think if you pulled him out of the situation, he would've said no, and he doesn't know to this day why he said yes."
Edwards denied rumors that the former senator had moved out of their 28,000-square-foot home in North Carolina, which was completed three years ago.
"Yes, he's still living in the house. Yes, they're still together," King said. "It was very clear that she loves her family and loves the family life that she has, and wants to preserve that."
The Edwards have three children. The oldest is 27, and the youngest, 3. Their 16-year-old son Wade died in 1996.
Elizabeth Edwards said her children know about the affair and that their father told them he acted inappropriately.
"The children pretty much know, I don't know what they heard in school, but they have computers," she said.
When thinking about her cancer, Edwards said she sometimes cries and cries and thinks of "things undone, people I'll leave behind."
"I cried and screamed. I went to the bathroom and threw up," Edwards wrote, according to the New York Daily News.
John Edwards publicly admitted the affair in an August 2008 interview with ABC News' Bob Woodruff.
"It was a huge judgment, mistake in judgment," he said. "But yeah, I didn't think anyone would ever know about it. I didn't."
She revealed in the interview that she had asked John Edwards for only one gift when they got married -- fidelity -- because her father's cheating had had a detrimental impact on her mother.
"It was really important to me partly because I had seen what happened to my mother when she caught my father cheating on her. I didn't want to go through that. It made her less than she could be, and I just did not want to see that happen to me, so that was the one thing I asked for. He willingly said yes," she told Winfrey.
Edwards told Winfrey she had no idea whether John Edwards was the father of Hunter's baby. John Edwards has said he and his wife believe he is not the father. However, his wife does not state that explicitly in the interview with Winfrey.
"And there is great speculation that your husband, John Edwards, is the father of that baby," Winfrey said.
"That's what I understand. I've seen a picture of the baby. I have no idea. It doesn't look like my children, but I don't have any idea," Edwards said.
When pressed by Winfrey, Edwards added that whether the baby is her husband's or not would make a different in her husband's life but not hers.
"This is the part where you have to concentrate on your own life. Whatever the facts are doesn't change my life, in that sense," she said. "I don't see an upside of making it part of my life. ? He doesn't know any more than I do about this."
In her book, Edwards apparently does not address the issue of who fathered Hunter's daughter.