Investigators pieced together some details about the events that led to their deaths: The girls, ages 5 to 16, were kept as prisoners in their home, starved and ultimately killed by their mother.
Their family has said little. There were no victim impact statements from Jacks' relatives, who attended the hearing, or anyone else who might have given voice to their personalities and how they suffered.
"We can't say what's worse - the terror of knowing what your mother did to your sisters or knowing that she's coming for you next," prosecutor Deborah Sines said.
In July, Jacks, 34, was convicted of four counts of felony murder, three counts of premeditated first-degree murder and four counts of first-degree child cruelty. She was acquitted of one count of premeditated first-degree murder in the death of her oldest daughter because the exact cause of death couldn't be determined.
The extreme decomposition made it difficult for experts to determine exactly how and when the girls died, but medical examiners said the three youngest children were most likely strangled and 16-year-old Brittany was probably stabbed.
Prosecutors said Jacks isolated her daughters from friends, family and neighbors
- anyone who could have protected them from her. U.S. Marshals found the bodies when they came to serve an eviction notice in January 2008.
Sines said authorities pored over records, every scrap of paper seized from home to learn more about them.
"It is easy to forget these children," Sines wrote in her sentencing memorandum. "Each child deserves attention at this sentencing."
According to the document, a high school counselor described Brittany as very motivated and smart. The girl told her counselor that she had to go to college and make money so that she could take care of her sisters. She was friendly, willing to help other students, a role model for others.
Report cards for the second child, Tatianna, called her "an ideal student and a delight to have in class" and spoke of her "beautiful personality and positive disposition." She also performed well on tests despite excessive absences.
Less is known about the younger two, N'Kiah and Aja, who attended an early child care program, Sines said.