Sid was Judge Clinton Sternwood's law clerk.
In March 1989, Sid went to the Twin Peaks Sheriff's Station, where Sheriff Harry S. Truman introduced her to FBI Special Agent Dale Cooper. She and Sternwood then left for the Great Northern Hotel.
Sid was present the next day at Leland Palmer's hearing for the murder of Jacques Renault and Leo Johnson's hearing for the arson of the Packard Sawmill. During a deliberation, she served drinks to Sternwood, Truman, and Cooper.