Samantha Sams, 40, and the child are both being treated at St. Joseph Regional Medical Center for non-life threatening injuries.
The accident happened around 1:00 Thursday afternoon and traffic was held up at the bottom of the Lewiston Hill for close to an hour.
"A 1997 minivan failed to yield when trying to cross inbound traffic on Highway-95 right at the Rose Garden," said Chief Deputy Roger Lanier. "Unfortunately it was struck by a 2014 Kenworth truck and an unrestrained four-year-old child was knocked out the passenger side window."
Sams was cited for failure to yield, no insurance and injury to a child for failure to restrain the child. Chief Lanier said it's fortunate the child isn't hurt too badly, but it's very important to always make sure children are strapped in and have the proper safety seats for their age.