When police arrived at UF Health Jacksonville hospital, the child's mother at first lied and said her daughter was watched by another baby sitter.
Later she admitted the child had in fact been with Graham.
The Medical Examiner's Office could not determine the cause of death.
An autopsy found multiple traumatic injuries to her head, torso and extremities, as well as fluid and swelling to the lungs and brain, according to authorities.
Graham's sentencing is scheduled for April 17.
No charges have been filed against the girl's mother.
David Chapman, a spokesman for the State Attorney's Office, said: 'The aggravated child abuse charge against Graham carries with it a 30-year maximum and reflects the findings of the Medical Examiner's Office, which indicated the cause and manner of death could not be determined.'