De Boer's television debut was an uncredited role in Freddy the Freeloader's Christmas Dinner, which starred Red Skelton and Vincent Price. De Boer's first major television work was as a regular in the CBC series 9B followed by a recurring role on the Canadian sketch comedy show The Kids in the Hall as Laura, girlfriend of Bobby Terrance (Bruce McCulloch). She subsequently appeared (as a different character) in their 1996 film Brain Candy.
Her first major TV role came in 1997, in the short-lived Sci-Fi Channel series Deepwater Black (also known as Mission Genesis) as Yuna. She followed that up with a role in the cult favourite science fiction film, Cube (1997). She was featured in episodes of the Canadian-produced SF series The Outer Limits alongside Robert Patrick (The Quality of Mercy) and Harry Hamlin (Monster).