The grieving mother of Krystal Bayron-Nieves, the 19-year-old cashier who was fatally shot during a robbery at a Manhattan Burger King, urged President Biden to help combat the gun violence plaguing the Big Apple on the eve of his visit.

“I want to tell Biden to change the system. To take the homeless out the street,” Kristie Nieves, 36, said at a press conference Wednesday through a Spanish translator.

She said she doesn’t want “what’s happening to me to happen to anybody else. All I want is justice for my daughter.”

Police said the teen was working the night shift at the fast-food joint on Jan. 9 when a man came in around 1 a.m., brandished a gun and demanded money.

Her family said there was only about $100 in the cash register.

The armed robber pistol-whipped one man, slugged the female manager, and, as he was leaving, turned and fired at Krystal, mortally wounding her, according to police.

“My daughter is very special to me. She was a kind daughter,” Nieves told reporters, at times so overwhelmed with tears that she had to stop talking.

Winston Glynn, a 30-year-old homeless former employee at the eatery, was later charged with murder in the death of the Puerto Rico native, who moved to the Big Apple to live with her mother and younger brother six years ago.

At the press conference at the mom’s civil attorney Sanford Rubenstein’s office, the lawyer said the “real question” is “how did a homeless man with a history of mental illness get a gun in this city?”

“Right now, what’s important to this mother is that it does not happen to any other family and that no other mother has to grieve the way she is for her beautiful 19-year-old daughter,” Rubenstein said. “Gun violence is a problem and it must be addressed.”

The presser came just before the president visits the city to meet Mayor Eric Adams and discuss the troubling surge in gun violence.

Biden announced his visit last week in the wake of the killing of two NYPD officers in Harlem.

Since he was sworn in as mayor on Jan. 1, five NYPD cops have been shot, a baby girl was shot in the face, a mentally ill man killed a woman by shoving her in front of an oncoming subway train and Krystal was gunned down in cold blood.

Nieves was particularly offended by a comment White House press secretary Jen Psaki made Monday in which she brushed off concerns about liberal cities’ soft-on-crime policies — joking on a left-leaning podcast that media coverage of violence in major cities like New York came from an “alternate universe.”

“I know there is a crime problem in the city because my daughter was murdered,” Nieves told Fox News in a separate interview out Wednesday.

“I know how she feels because I’m going through it. This has to stop,” she added tearfully, referring to the mother of the baby who was struck in the face by a stray bullet.

Rubenstein said at the press conference that Psaki should apologize to his client. 

“This is the real New York City. Gun violence is a problem,” he said.

Krystal had complained about the late-night shift, fearing for her safety in a neighborhood peppered with vagrants, her family has said.

Her mom last month told The Post she still feels guilty that she convinced her daughter to stick it out and go in to work on the day she was killed.

“[Kristal] say, ‘I don’t want to go. I’m scared,’” she said. “I say, ‘You have to go and be responsible.’ At 10 p.m. I wake her up to go and tell her, ‘You have to go. You have to be responsible. You have to get a better life.’”

“We need to change a lot of laws, we need more police and there is so much crime,” Nieves told Fox News. “We need to do whatever it takes to get the guns off the streets.”