Millerberg, 41, of North Ogden, pleaded guilty in June to third-degree felony counts of obtaining a prescription illegally, obstructing justice and abuse or desecration of a human body.
West told the woman he would have ordered a prison sentence of up to 10 years for the crimes, but said he did not because of her plea agreement with prosecutors which recommended the three zero-to-five-year terms run concurrent to one another.
The judge said that while she does get some credit for testifying about how her husband, Eric Millerberg, injected Alexis with a fatal mixture of heroin and methamphetamine, he noted she had already received a break. She has been out on bail, he said, and was allowed to move out of state.
"How many times do I have to give her credit for her cooperation?" West asked, adding that Dea Millerberg could have been charged with much more serious crimes, but was not because of her cooperation.
Millerberg's attorney, Michael Bouwhuis, asked for no jail time for the woman, telling the judge that she has been drug-free for three years and wanted to be with her children.
He told the judge that Millerberg had been abused by many people in her life, including her current husband, and struggled with drug issues even as she was rearing her children and going through nursing school.
"She was trying to hang on to some stability in her life," the attorney said of her client's drug use. "She got her nursing degree, bought a house."
Bouwhuis also said the woman took great risks to come clean and testify.
"There was a hit out on Dea from Eric," Bouwhuis told the judge.
Alexis' mother, Dawn Miera, said she didn't know what sentence she wanted for Dea Millerberg. She wanted the woman to learn a lesson, Miera said, but knew that the woman's testimony helped her find out what happened to her daughter and sent Eric Millerberg to prison.
"As a parent, your job is to protect your children, and I failed," Miera said tearfully as Dea Millerberg sobbed. "I do know Lexi was trying to find herself, and she found Dea."
Eric Millerberg, 38, was convicted by a jury in February of child-abuse homicide, obstructing justice, desecrating a human body and having unlawful sexual activity with Alexis. He was sentenced to life in prison in March.
Weber County Attorney Dee Smith told the judge Thursday that Dea Millerberg's willingness to testify was instrumental in prosecuting her husband.
"I don't know if we would have convicted Eric Millerberg without Dea," he said.
During Eric Millerberg's three-day trial, Dea Millerberg took the stand and testified against her husband of nearly 10 years.
She recounted that on Sept. 10, 2011, she picked up Alexis to baby-sit their kids, but instead she got high with the teen and her husband.
Through the night, Eric Millerberg injected Alexis with drugs three times, Dea Millerberg testified, once in the teen's neck. The three also attempted to have sex together, the woman testified, but they were too high.
Shortly after her husband injected Alexis for the third time, Dea Millerberg testified that the teen began to complain of being cold and shaky. The teen took a bath and, afterward, the Millerbergs helped her into the couple's bed. The adults then went outside to smoke.
When they returned, they found Alexis was not breathing. Dea Millerberg, who was at the time a licensed nurse, said she attempted CPR, but the girl never responded.
In a panic, the Millerbergs weighed their options. Ultimately, they decided to dump the teen in a remote part of Morgan County near the Taggart exit of Interstate 84.
Alexis was missing for 38 days before Eric Millerberg's friend, Eric "Peanut" Smith, broke the case for police. He testified that he helped Eric Millerberg move the girl's body Sept. 12, 2011 a day after the Millerbergs initially dumped it.
Smith led police back to the girl's badly decomposed body in October 2011.
The girl was found with her legs folded against her in a fetal position, her lower half stuffed into a garbage bag.
Dea Millerberg was granted "use immunity" in her husband's trial, meaning her testimony couldn't be used against her.
Charges were never filed against Smith, who made a deal with police in exchange for leading them to the girl's body.