A woman accused with her husband of forcing a teenage girl to be a sex slave for years in their mobile home pleaded guilty Thursday to a federal conspiracy charge in a deal contingent on her being sentenced to probation.

Marilyn Bagley, 47, admitted that she helped groom the girl to be her husband's sex slave after the teen moved into the couple's trailer 

Prosecutors said the girl was a mentally deficient runaway who was recruited at the age of 16.

Three men  have pleaded guilty in federal court to conspiracy to commit sex trafficking and are awaiting sentencing.

all four admitted going to the Bagley home to watch or take part in the sexual torture of the girl in exchange for money, cigarettes and other items.

Federal authorities began investigating the couple in February 2009 after the victim was taken to a hospital in cardiac arrest, which prosecutors said happened while she was being suffocated and electrocuted during a torture session.

Marilyn Bagley told The Associated Press last year that the victim collapsed while getting ready for work, not while being tortured. The couple had claimed the sex acts, including some the government characterized as torture, were consensual as part of their bondage, dominance, sadism and masochism lifestyle, in which they said the young woman was a voluntary participant.