She was life flighted to Good Samaritan Hospital in Downers Grove with possible internal injuries, among other injuries, Illinois Department of Natural Resources Conservation Police Sgt. Phil Wire said.
An ash tree broke and fell about 20 feet onto a picnic table where the woman was sitting. She was camping with her husband and son and after her husband and son left the table part of the large tree broke and fell.
Wire speculated high winds from a previous storm had played a role in the tree breaking. The weather had cleared up by the time of the incident at about 3:45 p.m. Saturday.
Utica Fire and EMS assisted at the scene.