Lori Berenson returns to Peru

(CNN) -- Lori Berenson, an American activist convicted of aiding Peruvian terrorists, returned to Peru after spending the holidays with her family in New York, family members said.

Berenson is on parole in Peru through 2015 but was given permission to leave the country to be with her family.

The move was controversial because some believed that Berenson would not come back to Peru to complete her sentence.

She returned Thursday night to Lima on a flight from Newark, New Jersey, said her mother, Rhoda Berenson.

"That is the law and she had to do it," she said.

Rhoda Berenson said the family's time together was appreciated and that she expects her daughter to return to the United States at the end of her sentence in 2015.

Under the permission granted by the court, Berenson could have remained in the United States until January 11.

Berenson was sentenced to life in prison in 1995 for collaborating with the Tupac Amaru Revolutionary Movement to attack the nation's Congress and overthrow the government. Her sentence was reduced to 20 years on appeal.

She was released from Lima's Chorrillos Penitentiary in November 2010 after a Peruvian court granted her parole.

In 2009, while in prison, Berenson gave birth to a son who was fathered by Apari, her estranged husband who is also her attorney. The boy lived with her in prison until her release.

CNN's Adriana Hauser contributed to this report.