The girl, said to be one or two months old was said to have a bruise on her head and near her eye.
The baby was found in a clean diaper a shirt, and a blanket.
Two women found her on the sidewalk and then brought her inside to a security guard.
Officials say the baby was on the ground for about 5 minutes.
"The baby had a blanket and the lunch lady from the other school came and took her into the nurses office," said Monica Fernandez.
The mother is said to be 37-years-old.
It is not clear if this incident falls under the Safe Haven Law.
The law states someone can leave a baby at a firehouse, police station or hospital which authorities believe the mother was trying to follow, however the injury to the baby could bring charges.
