Police found the baby girl Thursday evening in a small community 300 kilometres north of the city thanks to tips and police agencies that identified the woman whose image was captured on hospital cameras.
After the newborn was examined at a local hospital in Kirkland Lake and found to be unharmed, she was flown back to Sudbury, where she was reunited with her mother around 3 a.m. ET Friday.
A woman and her boyfriend, both 29, and from the Kirkland Lake area, are in custody, police said Friday. Investigators had previously listed the woman's age as 19 after her arrest.
Const. Bert Lapalme of Greater Sudbury Police Service told CBC News the female suspect was known to other police agencies, though he refused to offer further details.
After the baby's disappearance was discovered Thursday, police issued a nationwide Amber Alert and set up roadblocks around the city.