Deborah J. Cox, 58, of Naperville, is charged with two counts of aggravated criminal sexual abuse. Bond was set at $50,000.
Cox is accused of having a sexual relationship with a student at Neuqua Valley High School from January 2010 to May 2010. That student has since graduated, police said.
Investigators do not believe the aide was involved with any other students or that any of the alleged misconduct took place at school.
Cox will appear in court again on April 4 in Joliet.