HOUSTON (AP) _ A Harris County jury has found that a Spring woman caused her young son to have at least two unnecessary surgeries.

Laurie Williamson, 40, was convicted Thursday of injury to a child in connection with her son undergoing surgeries for implantation of a nerve-stimulation device and insertion of a gastric feeding button.

She now faces possible life in prison. Testimony in the punishment phrase of the trial began late Thursday and is set to resume Tuesday, the Houston Chronicle reports in its Friday editions.

State child welfare officials and prosecutors have said Williamson has Munchausen syndrome by proxy, a rare disorder in which a person fabricates or induces symptoms in others to gain attention.

Defense attorney Allen Isbell has denied that Williamson has the syndrome.

Prosecutor Mike Trent said Williamson manipulated doctors and her son's condition to get the surgeries.

"Perpetrators of this type of child abuse are very clever," Trent said. "She was very knowledgeable about the medical system. She was a nurses' aide at one time. She simulated and fabricated the symptoms that appeared to make the surgeries necessary."

Isbell has said that doctors told Williamson that her son needed the procedures.

Prosecutors said that over 10 years, Williamson took her three children to at least 500 doctor appointments. Prosecutors also said that she told the children they suffered from a rare illness and would not live past their teens.

When Child Protective Services took custody of the children in March 2006, officials said, they were malnourished. Two had feeding tubes and were in wheelchairs.

Expert witnesses for the prosecution testified during the trial that Williamson falsified her children's conditions.

Trent said Williamson also fabricated her children's conditions to solicit money from organizations and people, raising about $150,000 between 2000 and 2005.

"She was not simply seeking gratification through attention," Trent said. "She was actively seeking donations for support."

Isbell denied the allegations, saying, "She did not try to benefit from either her or her children's illnesses."

Williamson's son is 13 now. Her other two other children are 11 and 8. Child welfare officials said they placed the children in the care of a relative. Their mother is not allowed contact with them.

Officials said the children are physically fine.

Copyright 2008 The Associated Press.