AUSTIN — A former Pacelli High School teacher who had sex with a 17-year-old over several months was sentenced Thursday to 15 years of probation.

Mary Gilles, 28, must register as a sex offender and follow a large list of requirements under probation, which includes no contact with minors and and no access to the Internet without approval.

If she violates her probation, Gilles could go to jail for four years.

Gilles faced six counts of third-degree criminal sexual conduct with a 16-17-year-old as a person acting in a position of authority after she was accused of sleeping with one of her students several times in 2014. She pleaded guilty to two of those six counts in December in Mower County District Court.

According to a court complaint, Pacelli staffers saw Gilles with the student earlier this school year inside the school auditorium late at night, which prompted administrators to search the student’s school and personal email accounts. In addition, emails uncovered by school administrators revealed Gilles could have been pregnant by the student.

The victim and Gilles told police they had slept together four or five times between February and June, and continued to have sex in September, according to the complaint.

Gilles was suspended from teaching high school math and arrested at her home on Oct. 6. She was fired from her job the next day.