Luz Albrego claims officials at Urban Assembly School for Wildlife Conservation did nothing over the attack last May caught on cellphone video - and that one teacher even denied it ever took place on campus.
The Bronx school was open Thursday.
Cedeno faces charges of attempted murder, manslaughter, attempted manslaughter, two counts of assault and two counts of criminal possession of a weapon, the NYPD said.
The student who died was 16 years old, while the critically injured student is 15, sources told the New York Post.
The fight, which had been brewing since the beginning of the school year about two weeks ago, occurred in a fifth-floor classroom, NYPD Chief of Detectives Robert Boyce said.
Laboy was said by police to have pulled through surgery Wednesday and was in stable condition. He's nice. He's sensitive.
"He likes Nicki Minaj", she added. He'd wear stuff from H&M. "He likes Kylie Jenner", she said. He would be in the hallways. "They didn't hold him tight enough". They'd throw trash cans, textbooks, markers. "They were harassing him and that's when he did what he did", she told NY Post.
Officers say they recovered the knife at the scene. The school did not have metal detectors, though wands and detectors were brought in Thursday morning for random screenings.
His classmate, 16, is fighting for his life in hospital after suffering stab wounds to his chest.
A Bronx teen accused of fatally stabbing a bullying classmate was tormented with homophobic and racist slurs until he finally exploded, according to family friends.
As a result of the attack, the building was put on lockdown and many students were put into a state of fear.
Giselle Estevez, the mother of 9- and 13-year-old girls, said she'd seen violence at the school before and this latest attack was the final straw.
Some studies have found that black and Hispanic students in charter schools are more likely to attend predominantly nonwhite schools than their peers in traditional schools, partly because charter schools tend to be located in urban areas and are often established specifically to serve low-income students of color.
Family members say McCree and Laboy relentlessly physically and verbally tormented their son since the start of the school year. Grief counselors will also be available.
"There's absolutely no safety here", Alvarez says.
"You need to ask the right questions first, before they paint people, making it look like some mean person", Victor added.