DALLAS - A wealthy Texas woman has been charged with collecting and trading child pornography online in what experts say is a rare case of a woman being caught up in such activity.

Erika Susan Perdue has been undergoing addiction treatment since her April arrest on federal charges that she accessed child pornography from the computer in her $1.4 million home in the Dallas enclave of University Park.

FBI agents who raided the home found child pornography on the computer, and Perdue admitted she had been collecting it for 12 years, according to court records. She told investigators she used file-trading software every day to exchange images while her husband, a lawyer who specializes in intellectual property cases, was at work.

“I’ve seen cases of women collecting or trading child porn, but not very often and not somebody in that socioeconomic strata,’’ said Nancy Hagan, the longtime executive director of the Alliance for Children, a Fort Worth child advocacy center.

A four-count indictment asserts Perdue, 41, engaged in transporting, shipping, receiving, and possessing child pornography.