The Associated Press reports that the boys, aged 6 and 3, were placed in foster care after being found in Post Falls, near the Idaho-Washington border.
The suspect, 27-year-old Shannon Germanton, is charged with negligent driving. Idaho authorities are looking to add additional charges of child abandonment and child neglect.
After rescuing the children, law enforcement tried to contact Germanton on her cellphone, but police said she was "evasive about her whereabouts and kept hanging up."
She was found later inside a Spokane area home.