The judge accepted a plea deal for Marianne Bordt, 73, over objections from the boy's father, who wanted more prison time. Bordt, of Nufringen, Germany, had faced a potential death sentence for first-degree murder, but she was allowed to plead to a lesser second-degree charge for killing Camden Hiers in January 2010.
"I feel anguish and loathing for the person that is guilty of taking the life of my precious little boy," said Camden's father, David Hiers. "I want her to be punished as no person has ever been punished."
Hiers of College Park, Ga., an Atlanta suburb, wanted prosecutors to hold out for a 30-year term, but Circuit Judge Angela Dempsey imposed the agreed-upon sentence. Prosecutors also dropped an aggravated child abuse charge.
It was not immediately clear why prosecutors accepted the deal. Assistant Public Defender Andy Thomas declined comment.
Bordt's lawyers had been preparing an insanity defense claiming she did not understand her actions, in part because of injuries she suffered as a child from a Soviet bombing raid during World War II.
Hiers presented a slide show of photos of Camden, who had curly blonde hair and struggled to control his emotions as he recalled getting a call from police who told him there had been "a terrible event" on St. George Island where Camden had gone with his German grandparents.
They came to the United States every year to visit Camden and their daughter, Karin Hiers, who also lives in the Atlanta area. The boy's parents divorced when he was a year and a half old, and he split time living with both.
Bordt, wearing an orange jail jumpsuit with a pair of glasses pushed up on her thatch of short gray hair, intensely watched the billboard-sized pictures of Camden as an interpreter quietly translated Hiers' comments.
She made no statement, answering most of the judge's questions about the plea agreement by saying "yes" or "no."
Dempsey said she would recommend prison authorities continue medication Bordt has received at Florida State Hospital, where she has been held since shortly after her arrest. She initially had been declared incompetent to stand trial.
Dempsey later found she had become competent after treatment but allowed her to remain in the hospital.
Bordt would be 90 before she could be released because state law requires felons to serve at least 85 percent of their sentences.
Hiers told the judge that Camden was an energetic, happy, smart, curious and artistic child who liked basketball, riding his bike, drawing pictures and playing with toy cars and trucks that he arranged in neat lines.
"He was afraid of the dark and monsters under his bed like any child his age," Hiers said. "I told Camden that monsters were not real, but I was wrong. Camden did need saving from a real-life monster."
Authorities said Bordt's husband, Heinz, had gone shopping in nearby Apalachicola and returned to the rented beach house to find his wife fully clothed but dripping wet. He told investigators she tried to drown herself in the Gulf of Mexico after killing their grandson because she couldn't bear to see him "grow up in a divorced home."
Hiers said after the hearing that he and other family members never believed Bordt was mentally ill.
"We believe there was hate and unhappiness with the current situation between the two families," Hiers said.
Heirs filed a wrongful death lawsuit against the Bordts in federal court and hopes it may explain how and why his son died.