Jewell Hendricks accepted a plea deal in July for the smothering of her son Robert Hendricks in January.
Jewell Hendricks pleaded guilty to 1st degree murder of the 2-month-old boy and prosecutors agreed to drop a child abuse charge against her.
Prosecutors recommended the 15-year sentence.
Investigators say 25-year-old Hendricks smothered Robert with a sleeping bag when he wouldn't stop crying in January.
Investigators said that the baby had multiple other injuries as well, including a fractured skull and broken collarbone.
Hendricks called 911 on the morning of January 24, telling dispatchers her son was not breathing.
Robert was taken to the hospital where he was pronounced dead. Police say during questioning, Jewell Hendricks confessed to killing her son.
Robert's twin brother Daniel Hendricks was placed in state custody pending a DCFS investigation.
Police say the boy's father was at home at the time of the death, but was asleep.
A public defender said that Hendricks was suffering from postpartum depression at the time of the child's death.