Pima County prosecutors say 28-year-old Keshawna Higgins also was sentenced Monday to 10 years' probation.
Higgins previously pleaded guilty to child abuse after originally being charged with first-degree murder.
The Arizona Daily Star reports that Higgins was allowed to plead to the lesser charge after authorities learned she wasn't the toddler's primary caregiver.
Prosecutors say the girl's mother and grandmother still face first-degree murder charges in the case.
Authorities say 22-month-old Za'naya Flores died in January 2012 after suffering seizures and falling into cardiac arrest after being beaten and starved.
Court records show the child weighed barely 14 pounds when she died and had numerous bruises.