Simone Austin is facing first-degree murder charges after her daughter was stabbed to death in East Garfield Park Saturday, police said.
The medical examiner's office identified the girl Saturday night as Serenity Arrington and ruled her death a homicide as of Sunday.
Chicago police spokesman Tom Ahern confirmed that Austin was Arrington's mother Sunday evening.
Austin was arrested Saturday morning in the 3200-block of W. Fulton Blvd.
The girl received multiple stab wounds to the neck, according to the medical examiner.
The young girl's grandfather told ABC7 Chicago Saturday night that his 27-year-old daughter is responsible for fatally stabbing on Chicago's West Side.
Sylvester Washington said his granddaughter loved alphabet soup and watching movies with him.
"Y'all would have loved her. Sweet little girl. Man. Granddaddy little girl," he said.
Washington is now trying to understand how his beloved little granddaughter was taken from him. His neighbors offered their support and shared shock.
"To hear something like this happen on this block is just mind-blowing," neighbor Melanie Weaver said. "It's devastating. I couldn't imagine the pain and the devastation you know that they feel."
Chicago police responded just before 9:20 a.m. to the 3200-block of West Fulton Boulevard for a person stabbed.
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When officers arrived, they found a 5-year-old girl with stab wounds being treated by Chicago fire officials.
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Chicago fire officials transported the girl to Stroger Hospital with "multiple stab wounds," where she died a short time later.
"It's horrible, man. My own flesh-daughter did that. Man. Y'all don't want to have this feeling. No, I can't explain it," Washington said.
"It's a baby. She's 5 years old, getting ready for pre-K and all those things that she will never get to experience and her mom, she still had a whole lot of life in front of her so it's just like two lives lost," Weaver added.
Friends of the family said they are offering whatever support they can to help this family heal.
"For it to be somebody that young and that I have interacted with... It's like man, c'mon now, I didn't see this," family friend Darnell Richardson said.
Austin is due back in court October 19.
Sun-Times Media Wire contributed to this report.