A third co-defendant has pleaded guilty to the 2016 beating and burning death of an 83-year-old woman at her Georgia home.

Mina Christine Ellery, 19, admitted in court Friday her involvement in the brutal murder of Dorothy “Dot” Dow, a grandmother whose family operated a blueberry farm in north Meriwether County, about 50 miles southwest of Atlanta.

Ellery was sentenced to life in prison with a minimum of 30 years to serve for malice murder. She also pleaded guilty to armed robbery, home invasion and aggravated battery and was sentenced to 20 years in prison on each of those crimes. The sentences will run one after the other, according to Herb Cranford, district attorney for the Coweta Judicial Circuit.

Mina Christine Ellery (Photo: Meriwether County Sheriff's Office)

Credit: Meriwether County Sheriff's Office

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Credit: Meriwether County Sheriff's Office

Prosecutors say Ellery, along with four men, broke into Dow’s home Aug. 2, 2016. One man stole her purse while the other four interrogated Dow about where she kept her money.

RELATED: Woman, 83, beaten, burned in home invasion

Dow’s son lived at the home and was known to carry large sums of cash, according to information presented in court and confirmed to AJC.com by Cranford. But he was not there when the four allegedly attacked, and Dow couldn’t answer their questions.

They beat her, prosecutors said.

Dow’s arms were broken and her face was cut and bruised. Before they left, prosecutors said the crew poured lighter fluid down her back and set her on fire. They took several telephones from the home, authorities said in court, and Ellery admitted to grabbing Dow’s medical alert device from around her neck.

Still, Dow crawled to a phone to call for help. She used water from a sleep apnea machine to put out the flames.

Dow died more than 20 days later at Grady Memorial Hospital, Cranford said.

Two other co-defendants pleaded guilty to Dow’s murder, home invasion, theft and aggravated assault in December 2017. Justin Pierce Grady, 39, and Cortavious Deshun Heard, 19, had worked on the Dow family farm, AJC.com previously reported. Grady had worked for the family for many years, and Heard, who was Ellery’s boyfriend at the time, had been let go.

MORE: 2 plead guilty in beating, burning death of 83-year-old woman

Justin Pierce Grady (left), Cortavious Deshun Heard
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Grady and Heard have not been sentenced. A fourth person, Angel Harmon, is also accused in Dow’s death and has not been tried.

Sanquavious Cameron pleaded guilty to burglary and was sentenced to 15 years, with seven to serve in prison and the remainder on probation.

Ellery also pleaded guilty to burglary, identity fraud and financial transaction card theft for using Dow’s stolen bank card to withdraw $1,500 from an ATM, according to prosecutors.

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