Warrant Officer November Filander said she confessed to the crime on Saturday night following her arrest earlier in the day.
Jacobs’s body was found in a shallow grave at Imperial Primary School in Beacon Valley at about 14:00 on Saturday.
He was last seen at the old bus terminus in Mitchells Plain on Thursday at around 10:00.
An autopsy was reportedly being conducted with the cause of death unknown.
Filander said the 36-year-old mother was expected to appear in the Mitchells Plain Magistrate’s Court on Tuesday on charges of murder and abandonment.