As attorneys made opening statements early this week, defense attorney David Berceau claimed Beckering was not ignoring the fatal abuse, but rather she was unaware of it.
"When Christina died, my client was at work," he said.
Beckering was one of three people prosecutors charged last year in connection with Harms' death.
Cassandra Marie Shepard, 28, was Harms' legal guardian, and faces a murder charge. Beckering and her husband, Dale Beckering, were each charged with abuse of a vulnerable adult.
A jury convicted Dale Beckering in February. He is serving a sentence of up to 15 years in prison.
When Harms, who had fetal alcohol syndrome, was found dead on the floor of the family's home in Kearns, she had bruises on her body, bandages wrapped tight on her arms and fingers, and a pepper seed stuck under one eyelid.
An autopsy found she was severely dehydrated and had potentially fatal levels of Benadryl or a similar drug in her system.
Police and prosecutors say the adults would bind Harms' limbs with zip ties and keep her bound to a bar in a closet.
The closet had an alarm system and a knife was stuck in the door to prevent Harms from escaping. Inside the closet was a piece of cardboard with remnants of human feces and some scented pine cones and a sketch of Jesus Christ, officials have said.
"She was put in the closet by Cassandra not by my client," Berceau said. "My client didn't know about it."
Berceau told jurors Harms' injuries had all happened within a week of her death. Sherrie Beckering worked late into the night, and was busy caring for the children who lived in the home during the day, her attorney said.
Shepard's trial is scheduled to begin next year.