Both Mr. Bush, who died in November, and Ms. Fitzgerald denied any affair to the president’s biographer, Jon Meacham. “I was very close to her for a while. And liked her,” Mr. Bush told him. But did they have an affair? “No,” he said. As for Ms. Fitzgerald, she told Mr. Meacham: “It simply didn’t happen.”

Mrs. Bush was a singular figure in American life, the only first lady to see her son become president as well. (Abigail Adams, the wife of John Adams, had died by the time John Quincy Adams was elected.) But she was a more complicated figure than her grandmotherly image suggested.

A product of the World War II generation, she changed along with society. She resented when Wellesley College students protested her selection as commencement speaker on the grounds that she owed her only achievement to her marriage. Ms. Page recalled encountering Mrs. Bush at a Kennebunkport picnic in 1990 when the first lady asked her, “How can you work when you have young children?”

But years later, when Mrs. Bush received a citation that made no mention of her work promoting literacy and other social causes, she bristled at the focus on her family role. “I had not realized that I was a women’s libber,” she wrote in her diary, “but I am now.”

By the time Ms. Page interviewed her for the biography, Mrs. Bush boasted that all of her married granddaughters had children and worked outside the home. Still, she resisted activism. “Do I believe in equal rights for women? Yes,” she told Ms. Page. “But I wouldn’t put myself as a feminist, no.”

She struggled over the abortion issue, drawing from her experience watching her 3-year-old daughter Robin die of leukemia. She came to believe that the question was “when does the soul enter the body” and decided it was when a baby takes its first breath.

“Having decided that the first breath is when the soul enters the body, I believe in Federally funded abortion,” she wrote in her diary. “Why should the rich be allowed to afford abortions and the poor not?” She added, “Abortion is personal, between mother fathers and Dr.” But after her husband joined Ronald Reagan’s anti-abortion ticket in 1980, she kept her views to herself.