The incident happened as Widen's daughter walked the family dog, Marshmallow, around the block. A stranger saw the girl walking the dog alone and called police, the Chicago Tribune reports.
Widen told the publication that she can see most of the block from her home's windows. Walking the Maltese dog is the only time her daughter is unsupervised, she said.
The family lives in a safe area in the Chicago suburbs, she told "Good Morning America."
But a concerned neighbor contacted police, believing the girl was under the age of 5, the show reported.