Cynthia Dubois was taking care of Josiah Taylor at his father's home Tuesday when she found him unconscious. Authorities say she shook him, then waited at least 30 minutes before calling for help. He was pronounced dead at a hospital.
Dubois was to be arraigned Friday. Specific charges and her lawyer's name were not immediately available.
The medical examiner's office ruled Josiah's death a homicide after an autopsy found he died from battered child syndrome. The office said there was evidence his injuries occurred over a period of time.
Police are questioning the boy's father and his mother, who lives in the Bronx.