Editor's Note: This story contains graphic details about the brutal attack that left four children and their father dead. Reader discretion is strongly advised. 11Alive's Chris Hopper will have a full report tonight at 10 and 11.

GWINNETT COUNTY, Ga. -- The lone survivor of an attack that left five members dead told investigators that she saw her mother stab her father and her siblings.

Isabel Martinez is charged in the deaths of her husband, 33-year-old Martin Romero, and four of her children: 2-year-old Axel Romero, 4-year-old Dillan Romero, 7-year-old Dacota Romero, 10-year-old Isabela Martinez.

Police said they were stabbed to death in the early morning hours of July 6.

A fifth child, 9-year-old Diana Romero, survived the attack and was life-lighted to Children's Hospital of Atlanta in serious condition.

In newly-released Division of Family and Children's Services documents, Diana Romero described the terrifying events of that morning.

In an interview with investigators conducted on July 10, the child, who was set to attend fourth grade this fall, described her life before the stabbings.

Diana said that often played with friends and family outside in her neighborhood, specifically stating that she never went to her friends' homes and they never came to hers. She said she played board games and watched television with her siblings.

In the days before the attack, Diana said that her family had gone to Savannah and spent the night. She said she had fun playing in the water at the beach with her brothers and sisters. She said everything seemed normal on the trip, and that her mother and father didn't get upset with each other.

The 9-year-old became emotional when talking about what happened on July 6. She said no one other than her family was at the house when her mother began the attack.

Diana Romero said she saw her mother get a knife out of the kitchen.

(GoFundMe.com: http://bit.ly/2tz6fPI)

The child said her father was sleeping when her mother began stabbing the children, who were also asleep.

The 9-year-old said Isabel Martinez also cut herself.

Before her mother turned the knife on her, Diana said that she told her to forgive her, and that she loved her. She said that her mother told her she was going to the sky to see Jesus.

Diana said she cried and told her mother she didn't want to go see Jesus.

Photos from the scene (story continues below)

The 9-year-old victim said her mother took her into her father's room to watch him get up and show him what happened. She said her father went into the living room to try and get help, but as he walked to the door, Isabel Martinez began cutting him too.

Diana, who said she couldn't move, said she saw her mother then stab another of her brothers.

The 9-year-old said her mother wasn't crying or screaming during the attack. She said her mother called police after she cut herself.

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In a separate interview included in the DFCS documents, Isabel Martinez denied stabbing her family. She claimed a family friend murdered the children and her husband, and said, "The truth will come to light."

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In her first court appearance on July 7, Isabel Martinez displayed bizarre behavior, showcasing a wide smile for the cameras in the courtroom. She waved her arms and gave a thumbs up, prompting the judge at one point to caution her to "cut out the display for the cameras."

Martinez's preliminary hearing is set for Thursday, July 20.

Funeral services were held for the four children and their father on July 12.

A GoFundMe page has been set up for Diana Romero, who is continuing to recover from her injuries. Click here for information on how to donate.

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