LOS ANGELES (AP) — A nurse’s assistant who beat her young adopted son and daughter with cords, ropes and pipes and bound them with zip ties in their bedrooms while she went to work was sentenced Wednesday to as long as life in prison, prosecutors said.

Ingrid Brewer, 53, of Palmdale must serve at least seven years before being eligible for parole, but could spend life in prison after pleading no contest to two counts of torture in Los Angeles County Superior Court in Lancaster in December.

Brewer was arrested after the 7-year-old girl and 8-year-old boy were found huddled under a car in their pajamas in sub-freezing temperatures a few blocks from home in January 2013, said Deputy District Attorney Theodore Swanson.

The children were scarred and blistered and said they had been locked and bound with zip ties at times in separate bedrooms while Brewer worked at UCLA Medical Center. The brother and sister, who shared the same biological mother, had to communicate with each other through the walls of the home when they were tied up.

“The things these kids had to endure at that age it’s hard to read and listen to the testimony of those injuries without feeling some sort of sadness,” Swanson said.

Brewer’s arrest led to an internal investigation by the Los Angeles County Department of Children and Family Services into how Brewer was able to adopt the children despite abuse complaints about her as a foster mother.

“This is obviously quite unusual,” department spokesman Armand Montiel said. “Adoptive homes go through quite a bit of scrutiny and screening which is why this is troubling that this happened.”

Montiel did not immediately know the results of the department’s internal investigation.