Maria Shriver Surprises Oprah Winfrey on Chicago Farewell Show

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Winfrey keeps her arm around Shriver's shoulders at Chicago's United Center.

Maria Shriver made an appearance on Oprah Winfrey's surprise farewell show Tuesday in Chicago -- the day after her estranged husband, Arnold Schwarzenegger,  announced that he fathered a love child with a longtime household employee.

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"Well Oprah, for more than 30 years, you bestowed the most amazing friendship on me, given me love, support, wisdom and most of all truth," said Shriver, who worked with Winfrey and Gayle King (who was also on stage) at the same TV station in Baltimore in the beginning of their television careers. Read THR's Oprah play-by-play blog

"I know I would not have gone on without receiving those gifts from you," added Shriver as the audience applauded. "You believed in others so they could believe in themselves. You taught young women and men to focus on learning everything you can so they can give the world everything that they are."

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"The number of lives that are transformed because of you… you don't really have a clue how big those numbers are! Turn around and take a look at this!" Shriver added, as 64,866 flashed on the jumbo screens, representing those who had been affected by her generous scholarship funds. ("Take a look at this, not this," joked Shriver, gesturing at both her cut-out dress, which revealed her bare back, and the video screens. )

Next, Tyler Perry made an appearance and then the lights were dimmed as Kristin Chenoweth  performed with more than 300 Morehouse College students Winfrey had helped pay to put through school.

Shriver was spotted having lunch with Winfrey and King in Chicago before the show, according to a People report.

Earlier this week, Schwarzenegger admitted to fathering the child.

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"After leaving the governor's office I told my wife about this event, which occurred over a decade ago. I understand and deserve the feelings of anger and disappointment among my friends and family," he said in a statement to the Los Angeles Times, which first reported the story.

"There are no excuses and I take full responsibility for the hurt I have caused. I have apologized to Maria, my children and my family. I am truly sorry," continued the former governor of California. "I ask that the media respect my wife and children through this extremely difficult time. While I deserve your attention and criticism, my family does not."

Schwarzenegger and Shriver recently announced they were separating after 25 years of marriage, and that Shriver had moved out of their Brentwood home.

"This has been a time of great personal and professional transition for each of us," the couple told the Times in a joint statement. "After a great deal of thought, reflection, discussion and prayer, we came to this decision together. At this time, we are living apart while we work on the future of our relationship."

Shriver had hinted at trouble on her Web site just a few months prior, saying she was going through a time of transition and asking for advice.

Last Friday, she told fans on Twitter that she was "humbled" by their support. She has not yet spoken out on Twitter after the news of her husband’s out-of-wedlock child broke.

Since leaving office, Schwarzenegger has signed on to star in the drama Cry Macho. His reps at CAA also are shopping a package for a new Terminator sequel. In addition, he has partnered with Stan Lee on a Governator comic and animated series, with plans for a movie as well.

In addition to running her women's empowerment Web site, she recently served as a guest editor on an issue of Oprah Winfrey's magazine, O.

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