The woman, who can't be named for legal reasons, spoke to Inside Edition to defend the child who she says would never have intentionally hurt the little boy, Jaxon Hunter.
'There is no way it was done in any type of intentional way,' she told Inside Edition.
Six-month-old Jaxon was at the daycare centre when the girl allegedly dropped him on his head. Then prosectors say she stomped on his head to stop him crying.
Baby Jaxon was taken to hospital and two days later succumbed to his injuries and died.
The young girl, now, 11, has appeared in court charged with felony first-degree intentional homicide as an adult. She came into court crying and clinging on to family members with handcuffs around her wrist.
She's one of the youngest children ever to be charged with such a serious crime.
Her mum described her as 'beautiful' and 'intelligent' but did say she suffers from mental illness which was why she's been placed in the daycare centre for three days a week as a 'last resort' when they couldn't find help elsewhere.
Inside Edition asked the county Department of Human Services why a troubled child was allowed in the same facility as a six-month-old in daycare, but they didn't respond.
The girl is currently being held in the adult unit at the Winnebago Mental Health Institute on a $50,000 (US) cash bond.
'She's the youngest person there,' said her mum. 'She's 11 years old with women 40 years old and over.'
The girl's next court hearing is due October 11.