Sarah Ferguson faces charges of going "against the law in acquiring footage and violating privacy" of five children at one of the orphanages, the Anadolu Agency said. If convicted, she could receive a maximum sentence of 22 1/2 years in prison.
The trial began Friday, and Ferguson did not attend the opening session, the agency said.
Ferguson, the former wife of Britain's Prince Andrew, allegedly made an undercover trip to Turkey in 2008 during which she secretly visited the two state-run orphanages along with two British TV journalists. An indictment filed against Ferguson in January said the two journalists are being separately investigated.
The footage of the five children was filmed at the Saray Rehabilitation and Care Center orphanage on Sept. 22, 2008 near Ankara and shown that year on the British ITV program "Duchess and Daughters: Their Secret Mission." The filmed images appeared to show the children tied to their beds or left in cribs.
The government has accused the duchess of smearing Turkey's image, while saying at the same time that it would investigate and address any problems at the orphanages.
The news agency quoted her lawyer, Cansu Sahin, as saying the duchess is seeking an out-of-court settlement. On Friday, the court told Sahin that Ferguson should attend next hearing, Anadolu reported.
Canan Yildiz, a lawyer representing the five children and Turkey's Family and Social Policies Ministry, said her clients have been "harmed" and would like to join the public prosecution against Ferguson and the two British journalists who have been also indicted in the case and could be tried separately.
The court agreed to hear testimony from the five children who were filmed, but Yildiz said some of them are mentally retarded and others are handicapped, and that it would have been better if their testimony was taken at the orphanage.
Anadolu did not say when the trial would resume, and the lawyers in the case could not be reached for comment on Saturday.
One reason the Ferguson case angered Turkey's government is that it emerged during the country's long-standing effort to become a member of the European Union, despite opposition from some EU states about issues such as human rights and free speech in Turkey.