O'Connor, 76, also says she accelerated her retirement announcement by at least a year because then-Chief Justice William H. Rehnquist, who was battling thyroid cancer, told her he was not ready to leave the court, according to a Newsweek interview released Sunday.
"I was concerned about whether he had an intention to step down since his plans might have altered my own. It's hard for the nation to grapple with two (retirements) at once," she said.
After Rehnquist said he was staying, O'Connor announced her retirement in July 2005. Rehnquist died two months later.
O'Connor, who is still physically and mentally fit, said it was her plan to follow the tradition of previous justices, who enjoy lifetime appointments, to work until they die or are virtually incapacitated.
"Most of them get ill and are really in bad shape, which I would've done at the end of the day myself, I suppose, except my husband was ill and I needed to take action there," O'Connor said.
O'Connor currently divides her time between Washington and Phoenix, where she cares for her husband, John, who has Alzheimer's. Last summer, she reluctantly placed him in a care center in Phoenix and visits him often.
As a retired judge, O'Connor maintains an office at the Supreme Court, still draws a salary and fills in as a judge on the federal appeals courts.
O'Connor also recently served on the 10-member bipartisan Iraq Study Group and said she was surprised when the Republican leader of the panel, former Secretary of State James A. Baker III, asked her to serve on the group.
"I wasn't sure I should do it," she said. "It was so out of my field of judging. I don't know anything about the military."
While O'Connor called the assignment fascinating, she declined to say how she felt after President George W. Bush declined to embrace the group's call for a gradual troop pullout and more aggressive regional diplomacy.
"There are probably no perfect answers," she said.