A 40-year-old mother who police say placed a link on her MySpace page to an Internet site of sexually explicit material involving a girl whom her son was convicted of pimping now faces a felony allegation herself.

Sheila Marie Montgomery of Portland was arrested this week, accused of encouraging first-degree child sexual abuse.

At the time her son was sentenced in Washington state for promoting commercial sex abuse of a minor, Montgomery's MySpace page had a link to a "TNA" Internet ad that showed roughly a dozen photos of her son's victim in sexual poses along with prices for prostitution activity, a court affidavit says.

Her son, Zachary Driver, 20, was sentenced on Oct. 15 to 90 months in prison in King County following an agreement between the state of Washington and Oregon relating to compelling prostitution allegations stemming from activity in Portland and Seattle, said Glen Ujifusa, a Multnomah County deputy district attorney, in a probable cause affidavit filed in court.

Montgomery, on her MySpace page, called the victim a "Hoe," argued that her son is innocent and said the victim was a prostitute before she met her son, police said.

The girl told police that Montgomery knows she's 15 and was being prostituted by her son, since Montgomery at one point offered to help the girl get out of the life, the affidavit says.

At her son's sentencing, Montgomery also tried to confront the victim in the parking lot, yelling at her that she was a liar, the affidavit says.

Encouraging first-degree child sexual abuse is a Class B felony, punishable by up to 10 years in prison. Montgomery is accused of unlawfully and knowingly publishing, disseminating, exchanging and displaying a photograph and Internet site of sexually explicit conduct involving a child while aware the images involved child abuse.

Montgomery, who is due back in court next Thursday, didn't return calls Friday. One of her MySpace pages is titled "Mama" and suggests she's been taking classes since 2008 at Portland State University, noting the course name: Child and Family Studies.

She's been an outspoken opponent of Measure 11 mandatory minimum sentences, particularly after her son was convicted in 2006 of second-degree robbery. He initially was sentenced to 7 1/2 years, but the sentence was reduced to three years after he cooperated with authorities in identifying an accomplice.

According to the Portland Police Bureau, children as young as 12 are forced into prostitution. Portland police report an average of five cases of human trafficking each week, of which at least two of the victims are juveniles. Portland police estimate a pimp earns $800 to $1,000 a day from each juvenile victim.

On Wednesday, the Portland City Council is scheduled to vote on an emergency resolution to set aside $285,000 from the city's contingency fund for Janus Youth Programs and the Sexual Assault Resource Center.

Janus Youth Programs will set aside four to eight shelter beds for juvenile victims of sex trafficking, and the Sexual Assault Resource Center, based in Beaverton, plans to expand from two to four the number of victims advocates assigned to work with juvenile sex-trafficking victims in Portland.