Katrina Effert, 25, wiped away tears as an Edmonton judge ruled Friday she can serve a three-year suspended sentence with probation.
Effert was 19 when she secretly gave birth in her parent's basement in Wetaskiwin, south of Edmonton, in April 2005. She then tossed the baby's corpse over a fence into a neighbour's backyard.
Court of Queen's Bench Justice Joanne Veit said the public naturally grieves for the dead baby boy.
"But Canadians also grieve for the mother," she said. "This is a classic infanticide case — killing a newborn after a hidden pregnancy by a mother who was alone and unsupported."
Effert was twice convicted of second-degree murder and sentenced to life in prison with no possibility of parole for 10 years. But the Alberta Court of Appeal ruled earlier this year that the murder conviction was unreasonable and substituted one of infanticide.
Medical experts testified Effert had a disturbed mind when she killed her baby.
The Crown has already asked the Supreme Court of Canada to review the case.
Prosecutor John Laluk said Effert deserved four years in prison because she showed no remorse for her crime by lying to police and initially blaming her boyfriend for the killing.
The maximum sentence for infanticide is five years, but Veit said prison time is rarely handed out for such offences. She said the wildly inconsistent stories Effert gave police were actually "painful evidence" of her mental imbalance at the time.
As part of her probation, Effert must notify officials if she becomes pregnant again so she can receive assistance and counselling.
Veit described Effert as a person of good character with no prior criminal record who spent nearly six years living under restrictive bail conditions.
The judge said Effert, unlike most people her age, was not allowed to have a beer on a hot day and her parents had to chaperone her every move outside the home.
She also served the equivalent of 7 1/2 months in pre-trial custody and psychiatric care.
Effert still must serve 16 days in jail to finish her 90-day sentence on an additional charge of disposing of a body in order to conceal it.
Defence lawyer Peter Royal said he made a mistake by not appealing that conviction and will argue in court next week that his client should be allowed to serve it on weekends.