PITTSBURGH — A former state prison guard faces a 10-year federal prison sentence after pleading guilty Wednesday to forcing a 17-year-old boy into prostitution with the help of her boyfriend, whom she met when he was an inmate at the Western Pennsylvania prison where she worked.

Poshauntamarin Walker, 35, who last lived in Coatesville, near Philadelphia, pleaded guilty before a federal judge in Pittsburgh.

Like her boyfriend, Rasul Abernathy, 33, who pleaded guilty last month, Walker faces an agreed-upon 10-year prison term when she is sentenced Feb. 11. Abernathy will be sentenced Jan. 8.

Walker acknowledged forcing a 17-year-old boy the couple met online to sell himself for sex between December 2012 and March 2013 while she and Abernathy lived in North Versailles.

Although Walker didn’t plead guilty to charges involving a 16-year-old girl the couple was also charged with prostituting, she acknowledged responsibility for that behavior as part of her plea.

Details of the sex-trafficking charges are spelled out in an FBI search warrant unsealed in February, a few days after the couple was arrested near Philadelphia.

Abernathy and Walker placed personal ads for sex services, some of which pictured one or the other of the teens, and which had phone numbers investigators later linked to the couples. They paid cash for hotel rooms or sometimes used Walker’s debit card, and she would drive the boy to his “dates” with Abernathy as a passenger in the car, Smolar said.