Get ready: Oprah's coming to town. Maybe.

The media mogul - who successfully fended off a $12 million suit a dozen years ago, filed by a group of Texas cattlemen who claimed she defamed beef - could be in a Philadelphia federal courtroom as early as March 29 for another defamation case.

This time, she will face Lerato Nomvuyo Mzamane, former headmistress of the Oprah Winfrey Leadership Academy for Girls in South Africa.

Mzamane, who once served as an administrator at Germantown Friends School, contends that Winfrey defamed her in 2007 in the wake of a sex-abuse scandal that erupted at the private boarding school 10 months after it opened.

A dorm matron at the academy allegedly assaulted six girls, ages 13 to 15, and a coworker.

Winfrey suggested during the meeting with parents and a subsequent satellite news conference that Mzamane was not trustworthy and tried to cover up the allegations of abuse, according to the suit filed in Sept. 2008.

"I trusted her," Winfrey said of Mzamane during a meeting with parents. "When I appointed her, I thought she was passionate about the children of Africa . . . but I have been disappointed."

Mzamane, who now lives in Kenya, claimed Winfrey's comments made it impossible for her to find work for nearly a year.

Winfrey attempted to have the suit thrown out. But on Monday, a federal judge dismissed her request.

In a 128-page opinion, U.S. District Judge Eduardo C. Robreno concluded statements Winfrey made were "capable of defamatory meaning."

"The implication that [Mzamane] was aware of abuse . . . ascribes conduct which would render her unfit for her profession as an educator," Robreno wrote.

The judge ordered the trial to begin March 29.

Robreno rejected a claim that Winfrey intentionally inflicted emotional distress.

While Winfrey continues to talk it up on her famous couch, lawyers on both sides are keeping mum.

Responding to the judge's decision, Winfrey's Houston-based attorney, Charles L. "Chip" Babcock, issued a one-sentence statement.

"Oprah and Harpo [Winfrey's production company] await the opportunity to present the case in court," Babcock said, declining to answer any questions.

Mzamane's attorney, Timothy McGowan, was similarly curt.

"I spoke with Winfrey's attorney this morning," McGowan said yesterday. "We both agreed. We're both ready for trial."

If the case is not postponed - or settled out of court - Winfrey will give up her comfy couch in Chicago for a wooden chair at the federal courthouse at Sixth and Market Streets.

A spokeswoman for Harpo Inc. declined to comment when asked if Winfrey would consider hosting her show in Philadelphia for the duration of the possible trial.

During the six-week beef-defamation case in Texas, Winfrey famously hosted her show from a small theater in Amarillo.

The cattlemen charged that Winfrey knowingly made false and disparaging statements about beef during the broadcast of a 1996 show called "Dangerous Food." The cattle producers said Winfrey's comments caused cattle prices to plummet 11 percent the next day.

It was in the Texas panhandle city that her attorney, Babcock, introduced Winfrey to the psychologist Phil McGraw, who consulted on jury selection. McGraw, thanks in part to Winfrey's Texas exoneration, is now known widely as Dr. Phil.

Babcock, who worked at The Inquirer as a sportswriter and columnist in the early 1970s, has a lengthy roster of celebrity clients. Among them: Diane Sawyer, Warren Buffett, Bill O'Reilly, and George W. Bush, when he was president of the Texas Rangers.

Babcock's defense work in other well-publicized cases includes the 2003 Rhode Island nightclub fire and a defamation suit against McGraw.

His strategy for Winfrey's Philadelphia case is unknown.

Winfrey launched the Leadership Academy for Girls in January 2007, making good on an earlier promise to South African President Nelson Mandela that she would establish a school for needy girls in a country where fewer than half complete grammar school.

Winfrey's foundation donated $40 million and the school opened with a gala that drew Mandela, the filmmaker Spike Lee, and the singer Tina Turner.

In October 2007, Virginia "Tiny" Makopo was charged with 13 counts of indecent assault, assault, and criminal injury. The dorm matron's alleged victims included the girls and a 23-year-old coworker.

The revelations "devastated" Winfrey, who was herself sexually abused as a child.

In the aftermath of the charges, she met with parents and held the satellite news conference on Nov. 5, 2007.

Winfrey promised to "clean house from top to bottom" and announced she would not renew Mzamane's $150,000-a-year contract.

Winfrey accused academy officials of hiding facts and telling students to "put on happy faces and to never complain to me" when she visited.

"I feel that the girls were placed in an atmosphere where they were taught to be fearful and they were taught to, literally, be silenced," Winfrey said during the news conference. "And so, when you remove the systems and put in a different kind of leadership, all that will change."

The state-of-the-art school, on 52 acres about 40 miles south of Johannesburg, continues to operate. Next year, it expects to reach capacity with about 450 female students.

Contact staff writer Sam Wood at 215-854-2796 or samwood@phillynews.com.