Authorities say Silvia Johnson, 40, had sex with five boys at the parties for her daughter's classmates.
She pleaded guilty to two misdemeanor counts of sexual assault and nine felony counts of contributing to the delinquency of a minor. As part of a plea agreement, prosecutors dropped two counts of distribution of methamphetamine.
"She described herself as a 'cool mom,'" Detective R.J. Vander Veen wrote in the affidavit. He said Johnson told investigators "she was never popular with classmates in high school and now began 'feeling like one of the group.'"
Authorities say an investigation began after one of the boys told his mother about the encounters. One teen said he did think Johnson was cool, until - in his words - he "found out she was a pedophile."
Each sexual assault count carries up to two years in prison, and each count of contributing to the delinquency of a minor carries up to six years.
Johnson, who is free on bail, held parties for the boys almost weekly between October 2003 and October 2004, authorities said.