OMAHA, Neb. (AP) — A former Nebraska teacher who fled to Mexico with a 13-year-old student was sentenced Thursday to eight to 10 years in prison.

Kelsey Peterson, 27, pleaded guilty in January to two state counts of first-degree sexual assault of a minor. She is to serve her sentence simultaneously with a six-year federal prison sentence for transporting a minor across state lines to have sex.

She also must register as a sex offender.

Authorities said Peterson was the boy’s sixth-grade math teacher at Lexington Middle School during the 2005-06 school year and started having sex with him in November 2006.

They said she fled with him to Mexico after the district’s superintendent confronted Peterson about allegations of an inappropriate relationship with the boy. She was arrested a week later in Mexico after the boy called his mother.

The Associated Press is not naming the boy, now 15, because he is a victim of a sex crime. He was an illegal immigrant in the United States when he left with Peterson and returned to Nebraska from Mexico after being granted a temporary humanitarian parole by the Department of Homeland Security. In January, he applied for a special visa designed for victims of certain crimes.

Amy Peck, the boy’s attorney, said the family “does not wish for Kelsey Peterson to serve any more time than the federal sentence imposed.” Peterson had faced up to 50 years in prison on each of the state charges.

Dawson County Attorney Liz Waterman called the sentence fair.

Peterson, whose teaching license was revoked by the state this year, was credited for nearly a year of time already served and could get out a year early for good behavior.

Her attorney, James Martin Davis, said she did not plan to appeal the state sentence.