One instant, My’onna Hinton was taking a bite out of a slice of pepperoni pizza almost as big as her 4-year-old face, smiling and mumbling “good” through a mouthful of cheese and tomato sauce.

A moment later, the little girl with ponytails was shot through the neck by an 8-year-old playmate as the children were at a neighbor's apartment the night of May 25 in Southeast Washington.

The boy “thought it was a toy,” said the girl’s mother, Brayonna Hinton, 43.

The boy, blood on his hands and shirt, ran from one apartment building to the next to find the girl’s mother, who raced over while dialing 911.

“I didn’t mean do it,” the boy told Brayonna Hinton. “I’m ­sorry.”

My’onna survived but remains hospitalized with injuries to her spine. Her mother said the girl, who likes to dance and wants to be a model, just started moving her hands again in the past few days.

D.C. police said they are vigorously investigating and searching for a person to arrest. But a crucial piece of evidence is missing: the gun.

My’onna had been with a group of children at an apartment in a building adjacent to the one where her family lives in the Oak Park complex on 30th Street SE in the Buena Vista neighborhood. Hinton said one boy found the gun in a drawer and passed it to the 8-year-old, who fired it.

In the moments between the shooting and Hinton racing to the other apartment, the gun disappeared. Hinton said no adults were there when she entered the apartment and found her injured daughter.

Police would not comment on specifics but said they are making “good progress” on the case.

“We are determined to hold someone accountable for this,” D.C. Police Chief Peter Newsham said, confirming that the gun is missing and noting the severity of My’onna’s injuries. “And it won’t be the other child. It will be the adult for leaving that gun unsecured.”

Police had described My’onna’s condition as grave and said after the shooting that she was “fighting her life.”

This week, the chief said of My’onna, “She will never be the same.”

Before she was confined to a hospital bed, for days unable to move her hands and struggling to talk through a breathing tube, My’onna liked to play with her bike and dance to pop music. She had auditioned to model children’s clothes, her mother said, and had been preparing for her first photo shoot.

Now, her mother said, “she says she loves me and tries to rub my forehead.”

Hinton said her daughter says ‘yes’ when asked if she understands what happened to her, but she’s not really sure that My’onna fully comprehends.

She said the bullet went into one side of her daughter’s neck and came out the other. Doctors told her the bullet broke a bone, which in turn damaged part of the spinal cord. At the moment, she can’t swallow.

Hinton said the 8-year-old keeps asking when My’onna is coming home. “He thinks she’s up and running,” Hinton said. But she added, he has nightmares about the shooting.