PHILADELPHIA -- The ex-headmistress of Oprah Winfrey's school for girls in South Africa sued the talk show host for defamation, claiming Winfrey falsely suggested she tried to cover up abuse at the school.

In widely reported remarks last year, Winfrey suggested that Nomvuyo Mzamane, 39, of Philadelphia, knew about alleged abuse by a dorm matron and tried to cover it up, Mzamane says in the lawsuit.

Her lawsuit, filed in Philadelphia Common Pleas Court on Friday, seeks more than $250,000 on five defamation and related counts from Winfrey and her production company.

"The thing that hurt my client the most was when Oprah said, 'I thought she cared about the girls of South Africa,'" said Mzamane's lawyer, Timothy McGowan. "It was devastating. She loved those girls."

A spokeswoman for Winfrey says the company has not seen the suit and plans no immediate comment.

Former dorm matron Tiny Virginia Makopo, 28, is charged with abusing six students at the $40 million school for poor girls that Winfrey built. Makopo allegedly tried to kiss and fondle the victims and is also accused of kicking and hitting some of them.

Makopo has pleaded innocent to 14 charges of indecent assault, assault and criminal injury. Her trial is scheduled to resume later this month in South Africa.

Mzamane, a native of Teyateneneng, Lesotho, came to the United States for college and graduate school. She previously held a leadership post at the Germantown Friends School, a Quaker school in Philadelphia.

Winfrey learned of her background and recruited her in late 2006 to run the Oprah Winfrey Leadership Academy for Girls near Johannesburg. Mzamane worked at the school from about January 2007 through October 2007, when she learned, during a meeting with Winfrey in Chicago, that allegations of sexual and physical abuse had surfaced and she was being put on leave.

Her contract, which paid about $150,000 a year, was not renewed after December. She now is back in Philadelphia, but cannot find work in her field because Winfrey's remarks about her are easily found on the Internet, McGowan said.