There were no signs of the other two children, authorities said Saturday.
Authorities have said that data from the vehicle’s software suggested the crash was deliberate. They said the SUV had stopped at a coastal highway overlook before speeding straight off the cliff and plummeting 100 feet (31 meters) into the rocky Pacific Ocean below.
Sarah Hart pleaded guilty in 2011 to a domestic assault charge in Minnesota over what she said was a spanking given to one of her children.
Bruce and Dana DeKalb, the family’s next-door neighbors in Woodland, Washington, called child welfare officials last month because the couple’s 15-year-old son, Devonte, had been coming to their house almost every day for a week, asking for food. They said the teen claimed his parents were “punishing them by withholding food.”
Devonte, a black boy who is still missing, drew national attention after he was photographed in tears while hugging a white police officer during a 2014 protest.
The discovery of the body Saturday follows a two-day storm that swept through Northern California.
The sheriff’s office noted that it is not uncommon after a significant storm that items would surface or wash onto the beach.
“The Mendocino County Sheriff’s Office is monitoring the ocean conditions to see when further searches might be safely conducted,” Barney said. “This evaluation includes the use of divers if conditions permit.”