When Jenn and Mike Nealey of Manassas needed to hire a babysitter for their three young children in early 2012, it seemed they had the perfect candidate.

Jessica Fraraccio, 22, was well-known to the Nealeys. The devout Catholic wanted to spend her life around children. She was studying child development and planned to start her own day care someday, she told them.

Fraraccio’s guilty plea to felony murder and child abuse in a Prince William County courtroom Monday was a shocking admission that she had done the unthinkable. She admitted to smothering and killing 23-month-old Elijah Nealey in the summer of 2012.

She couldn’t get the toddler to stop crying, Fraraccio told police, so she picked him up and covered his nose and mouth with her hand.

“She was going to give him lunch,” Mike Nealey, a 40-year-old federal IT contractor, said in an interview. “An hour later he was dead.”

Elijah Nealey (Family Photo)

On that August day , the Nealey’s two young daughters, 5 and 7, went to a neighborhood park with their grandmother. It was about noon, and Elijah stayed behind with Fraraccio because he was due for a nap.

An hour or two later, Fraraccio called 911. Elijah was unconscious, and she was performing CPR. By the time paramedics arrived, it was too late. He never woke up.

At first, Fraraccio said the boy had slipped in the tub and hit his head, but months later she told police that wasn’t true, Assistant Commonwealth’s Attorney Teresa A. Polinske said in court.

In the end, Fraraccio told police that Elijah was upset when the others left for the park and stood by the window and cried, Polinske said.

Fraraccio became frustrated with his crying. When Elijah sat down on a small chair at a play table, Fraraccio pulled the chair out from under him, Polinske said. The boy hit his head on the table and floor.

“He was screaming and crying,” Fraraccio told police, according to the prosecutor.

Fraraccio then picked Elijah up and carried him upside down with her hand over his nose and mouth and walked him around the house, the prosecutor said. At some point, he bit her finger. “His last defense,” Fraraccio would say later.

The babysitter told police that she put Elijah in the bathtub and began to run water, in hopes he would be okay. The boy vomited and his eyes rolled back. Eventually, she carried him to a bedroom and called for help.

Sandra Drewniak, Fraraccio’s attorney, said in court that her client never intended to kill Elijah and has shown “extreme remorse.”

As part of a plea deal, prosecutors dropped a child abuse charge from a separate incident. She will serve a minimum of seven years in prison and could receive up to 50 years. Her sentencing is set for January.

For months after Elijah’s death, the Nealeys believed Fraraccio’s original story that their son had fallen in the tub. Mike Nealey said he wondered what would have happened if he had put in a rubber mat on the tub floor. He also blamed his son — why wasn’t he more careful?

The Nealeys’ relationship with Fraraccio began when Jenn Nealey was laid up after surgery in January 2012. She needed help with the children as she recovered. Jessica fit the bill, especially because the Nealeys knew her parents.

The babysitter was shy at first, Jenn Nealey said. Soon, though, Fraraccio began to engage the kids. She would show them how to bake and oversee living-room dance parties.

Her parents, Paul and Mary Fraraccio, declined to comment Monday.

Friends and family, in interviews and letters filed with the court, said they know Fraraccio as a kind and giving person.

John Stine’s children became friends with Fraraccio when she attended Holy Family Academy in Manassas, he said in a recent interview. Stine was impressed with the creative, outgoing and friendly girl. She liked to take photos with an older camera and collected the photos in a scrapbook. Others said in letters that Fraraccio likes to sew and bake and volunteered at the library and nursing homes.

“She is incapable of wishing evil; in high school, she wouldn’t even gossip about the girls everyone ‘hated,’ ” one friend wrote in a letter to the court.

Stine said Fraraccio was in anguish over the crime.

Prince William Commonwealth’s Attorney Paul B. Ebert (D) said he has dealt with many ­cases in which babies have been accidentally shaken to death. Fraraccio’s actions — smothering Elijah to make him be quiet and accidentally killing him — were particularly egregious, he said. Still, he added: “You don’t think a babysitter who is as personable and caring as she appeared to be would do something like that.”

The Nealeys said the memory of their son is constant. In their Manassas home — they have moved from their old place, in part because of what happened — the street sign “Elijah Way” sits on the mantel. Next to it, there’s a drawing of Elijah reproduced from a photo. In it, the boy is wearing a fedora and has a slight grin — a pose that reminds Mike Nealey of his grandfather.

Elijah was beginning to express himself, his parents said, and the boy always had a big grin on his face and a desire to say the few words he knew. His favorites were “rrrooaar” and “Piderman,” his way of saying Spider-Man, his family said in an obituary.

When Elijah’s birthday passed in September, Jenn Nealey said she thought about how she should have been enrolling him in preschool. The couple try to remind their daughters of some of the good memories, but don’t dwell on what happened.

His two sisters adored their little brother, the Nealeys said. They often dressed him up like they would their dolls. He didn’t seem to mind, they said.

After the hearing, Mike Nealey said he and his wife felt some measure of relief. They want to move forward.

“We never would have dreamt of this,” he said of the Jessica Fraraccio whom they thought they knew. “I don’t know how to process it.”