Sally was Derek's Co-worker and boyfriend before she left to a university.
Sally is a girl who has a part time job at Smelly Nellies, a small restaurant. Sally is a good girl who likes to help others and doesn't like it when guys play it cool with her. She's also good at giving useful advice to others like Casey. Sally is smart as well. This is shown when she tells Derek she is going to UBC. A college in Vancouver.
Derek dated Sally during part of season 3 and 4. They met in the episode "When Derek Meets Sally." Derek tends to listen to and obey Sally more readily than anyone seen on the show so far. Unfortunately, Sally announced in "Derek Denies Denial" that she was attending a college in Vancouver, leading to their breakup. He considered following her, dropping out of grade 12, and getting a job there in "Happy New School Year", but was persuaded by his family to stay. In this episode, they really truly breakup.