( CNN ) -- A woman convicted in the 2002 kidnapping of Utah teenager Elizabeth Smart pleaded guilty in the attempted kidnapping of Smart 's cousin a month later , court officials said Monday . In exchange for Wanda Barzee 's plea of guilty but mentally ill to one count of conspiracy to commit aggravated kidnapping , prosecutors dropped state charges against her in Smart 's abduction , said Nancy Volmer , spokeswoman for Utah state courts . Barzee , 64 , pleaded guilty in November to federal charges of kidnapping and unlawful transportation of a minor in connection with Smart 's abduction . As part of that plea agreement , she agreed to cooperate with the state and federal cases against her husband , Brian David Mitchell , federal prosecutors have said . Barzee and Mitchell were accused of abducting Smart , then 14 , at knifepoint from her bedroom in her family 's Salt Lake City home in June 2002 . Smart was found nine months later , walking down a street in the Salt Lake City suburb of Sandy , Utah , in the company of Barzee and Mitchell , a drifter and self-described prophet who calls himself Emmanuel and had done some handyman work at the Smarts ' home . The month after Smart was kidnapped , prosecutors alleged , Barzee and Mitchell attempted to break into the home of her cousin , but were unsuccessful . The girl was 15 years old at the time , according to CNN affiliate KSL . She is not named in court documents . `` Mr. Mitchell 's attempt was thwarted when the minor child awakened , which caused Mr. Mitchell to flee , '' the court documents said . Following her arrest in 2003 , Barzee told authorities that she and Mitchell went to the home in order to abduct the girl , and planned to hold her , along with Smart , in the couple 's camp in the mountains , according to court documents . Sentencing is set for May 21 on the state charge , Volmer said . Barzee faces between one and 15 years in prison , but prosecutors have agreed to allow that sentence to run concurrently with her federal sentence , according to court documents . Federal prosecutors have recommended a sentence of 15 years in prison for her in exchange for her cooperation against Mitchell . Federal sentencing was set for May 19 , but a spokeswoman for federal prosecutors has said a sentence would not be imposed until Barzee 's cooperation against Mitchell is complete . At the hearing in federal court , Barzee apologized to Smart , according to a transcript . `` I 'm greatly humbled as I realize how much Elizabeth Smart has been victimized and the role I played in it , '' she said . `` I 'm so sorry , Elizabeth , for all the pain and suffering I have caused you and your family . It is my hope that you will be able to find it in your heart to forgive me one day . '' Barzee had been housed at the Utah State Hospital while courts determined her competency as well as Mitchell 's . After years of being declared incompetent , she recently was declared competent to stand trial , according to the Salt Lake Tribune newspaper . A state court had ruled she could be forcibly medicated , and that ruling led federal prosecutors to proceed with bringing a case against the couple , the Tribune said . At a competency hearing for Mitchell in October , Smart , now 21 , testified that she had been held captive in Utah and California . Just after her abduction , Mitchell took her to a wooded area behind her home and performed a mock marriage ceremony with her , she said . During the nine months of her captivity , Smart testified , no 24-hour period passed without her being raped by Mitchell . U.S. District Judge Dale Kimball has not yet ruled on Mitchell 's competency . State court proceedings are on hold pending the outcome of the federal case . CNN 's Ashley Hayes and Eliott McLaughlin contributed to this report .
In exchange for plea , Barzee 's state charges in Smart 's abduction have been dropped . Sources : Smart , husband tried to kidnap Smart 's cousin , after taking Smart . Barzee , husband kidnapped Smart -- then 14 -- in Utah in 2002 , prosecutors say . Barzee already has pleaded guilty to federal charges in Smart 's kidnapping .