Instead of the bullet lodging in the book as planned, it accidentally passed through, killing 22-year-old Ruiz in front of the couple's three-year-old child and nearly 30 onlookers at the pair's Halstad home.
According to local media, 30 people - including the couple's young daughter - witnessed the shooting.
"This comes from the heart, where you shot him", she said during Monalisa Perez's sentencing at the Norman County Courthouse.
Brue told the Star-Tribune Monday, "I expect her to be sentenced with what is outlined [in the December 2017 plea agreement]".
Before performing the stunt Perez tweeted: 'Me and Pedro are probably going to shoot one of the most risky videos ever.
The couple thought a book would stop the bullet, but it did not.
As part of her punishment, usatoday reported a Norman County judge on Wednesday also banned Monalisa Perez from ever owning a gun again.
She added: "All the insane stuff will [be] on his channel and mine. will be our family life!" However, the bullet went through the book.
At the time of her arrest, Perez insisted that her boyfriend had been 'trying' to get her to do the shooting stunt for a while before agreeing. A 19-year-old Minnesota woman, charged with manslaughter for fatally shooting her boyfriend in the chest, in a stunt for a YouTube video, was sentenced to 6 months in prision an March 14, 2018.
The reality [is] that this foolish stunt was dreamed up, planned, and executed by Pedro Ruiz, and the defendant wrongfully and tragically relied on his assurances that the stunt was safe.
Members of Ruiz's family are expected to give statements to the court during sentencing before Judge Jeffrey Remick, the prosecutor said.
She said: "He had told me about that idea, and I said, 'Don't do it".
Perez's YouTube channel, which has 25,700 subscribers, shows her life with Ruiz in Halstad, Minn., and their various pranks and stunts. Since Ruiz's death, the view counts on the videos have gone up and the comments sections are dominated by remarks about the shooting.
Ruiz's death came whilst holding a hardcover encyclopedia against his chest while imploring Perez, standing a foot away, to fire a pistol to see if the bullet would go through the book.