LOGANVILLE, Ga. – It was the kind of phone call from hundreds of miles away that Maria Salazar could have never fathomed answering. Her cousin’s family was killed inside their own home—and the suspect is the wife and mother.

“We got the call. We just couldn't believe it,” Salazar, Martin Romero's cousin in Chicago, said about getting the tragic news about her family.

At about 5 a.m., Gwinnett County Police responded to a 911 call out of in Loganville, Ga., from whom they believe was 33-year-old Isabel Martinez. It was a bloody scene that first responders won’t soon forget.

“This is a horrendous crime. We don't have a motivation. But when our officers got here, they placed a female into custody,” Cpl. Michele Pihera, Gwinnett County Police spokesperson, said Thursday morning.

Police found the knife used to kill Martinez’s husband, Martin Romero, 33, as well as their children, Isabela Martinez, 10, Dacota Monserrat Romero, 7, Dillan Martin Romero, 4, and Axel Oliver Romero, who would have turned 2 in August, inside their home at 509 Emory Lane.

They also found the couple’s fifth child, 9-year-old Diana Romero brutally stabbed, but alive. She was rushed to the hospital and remains in the ICU at Children's Hospital of Atlanta, according to family members.

“What prompts a person to take the life of such innocent children and her spouse is something we may never understand. This is a horrendous crime not only for the victims but for the extended family, neighborhood and community,” Pihera said. “We are hoping and praying that the remaining victim survives her injuries and makes a full recovery.”

The Gwinnett County Police tweeted Friday that Diana was awake and talking and that she is surrounded by family.

Salazar said that her cousin was a family man and that Isabel loved getting the family together.

“He loved music singing karaoke. Getting people together, making food, getting everyone involved and getting family together,” Salazar remembered. “[Isabel’s] the same. She just enjoyed having company over—getting everyone over, that family environment.”

Martin, Isabel and their five children lived in Chicago until recently when they moved to Gwinnett County.

Salazar visited them in December for her godchild, Axel’s baptism.

“We visited a lot. We tried to get down there.”

And they seemed happy, she said.

"They were very happy. [Isabel] was a stay-at-home mom, very devoted to her children. Always out with them, played with them, watch them. They loved riding their bikes, playing tag."

But all of the BBQs and smiles came to a screeching halt when Martinez’s father died in Mexico just a few weeks ago, Salazar said.

“She was depressed after death of her father. Only thing that could've triggered. She may have fallen into a very bad depression,” she said.

PHOTOS | Stabbing leaves several children, one man dead in Loganville

Isabel, whose full name is Maria Isabel Garduno-Martinez, is a “Mexican national who illegally entered the United States and is in the country unlawfully,” U.S. Immigration and Customs Enforcement’s Southern Region spokesman, Bryan Cox, confirmed Friday.

“This is her first encounter with ICE so we cannot estimate how long she’s been in the country; she crossed the border at an unknown time [or] location,” he continued.

She is currently being held at the Gwinnett County Jail, refusing legal counsel. She is charged with six counts of aggravated assault with a deadly weapon, five counts of felony murder and five counts of malice murder.

In court Friday morning, she insisted to the judge that she would represent herself.

And as she left the courtroom, Isabel said, “For me, the hope and the attorneys are always going to be the people and my faith. Those are my attorneys, that is why I am here. Nothing else matters, I am representing the people that are humble, hardworking, the people who suffer and those who have a lot of charges so they understand everything is possible with God."

Martinez's preliminary hearing is scheduled for July 20.

Two GoFundMe pages have been created, including one by Salazar and another by Hallie Romero, for the family’s expenses.

NBC Chicago contributed to this report.