ST. STEPHEN, N.B. - A 20-year-old New Brunswick woman was sentenced to 30 months in prison for criminal negligence causing death in the slaying of her newborn boy, a graphic case that was an example of "wanton and reckless disregard," a judge said Tuesday.

Sarah Russell was originally charged with manslaughter, accessory after the fact and disposing the body of a newborn after her child was stabbed in the heart within minutes of being born. But in November those charges were dropped and she pleaded guilty to the charge of criminal negligence causing death.

Russell's boyfriend, Rodney Miller, pleaded guilty in September to first-degree murder for fatally stabbing the child. He is serving a life sentence with no chance of parole for 25 years after confessing his role in the child's death.

The boy was stabbed three times, wrapped in a towel and a blanket, doused with gasoline and set on fire in a wooded area behind their home in Moores Mills in southern New Brunswick on Jan. 17, 2009.

Court had heard that Russell was afraid of Miller, but provincial court Judge David Walker said he saw no proof of that.

Walker said Russell did nothing to protect the child and hid the pregnancy and birth.

Russell showed a "wanton and reckless disregard to provide the necessaries of life to her child," Walker said, adding that she didn't seek any medical help during her pregnancy.

"I cannot accept she was not able to seek help on or before the day of birth."

Russell wept quietly as she was led from the court.

Crown lawyer Jim McAvity said he thinks the sentence for Russell's "crime of omission" is enough to reflect society's abhorrence to her actions.

"She didn't do what she should have done starting back when she knew ... that her to-be-born child was in peril," McAvity said.

"She didn't drive the knife through his heart and that is essentially the difference here."

Miller and Russell were arrested Jan. 29, 2009, on suspicion they had concealed the birth of a baby boy.

For months, social workers believed Russell had been pregnant, but she consistently denied it.

But during an escorted visit on Jan. 22 with her first child -- who is in foster care -- social workers said she no longer appeared pregnant.

Details of the case began to unfold after Miller was taken into custody and told police that the baby had been born alive, but was then killed.

During a videotaped police interrogation, Miller alleged that he and Russell talked about killing the child more than three months before the birth.

But Russell's defence lawyer, Randy Wilson, said Tuesday that neither he nor the Crown believe that allegation.

While Wilson had asked for a sentence to be served in the community, he said his client should do well if she is given a chance to receive education in prison.

"I don't think she's a violent person. I don't think she's a malicious person. I think she'll do just fine," he said.

Psychological reports prepared for the court stated that Russell is naive, has a lower than normal level of intelligence, avoids unpleasant thoughts and is easily influenced by others.

During Miller's trial, social workers testified they suspected Russell was pregnant despite her assertions to the contrary, but had no legal power to compel her to take a pregnancy test or take her into their care.

Kelly Lamrock, the province's minister of social development, has promised to look for ways to better protect children who may be at risk from their parents.

The Conservative Opposition has proposed legislation that would allow a mother to leave her baby within 72 hours of birth at a hospital emergency room without the risk of legal action for abandonment. The baby could then be put up for adoption.

But Bernard Richard, New Brunswick's child and youth advocate, has said such legislation would not have helped in this case.

He said the government needs to explore a variety of options in order to protect newborns.

Russell was given four months of credit in remand, meaning she has to serve 26 months in prison.