Ms. Halpern (fl.2013) was a trigonometry teacher at Robert E. Lee High School. On October 7, 2013, she caught Elena Gilbert writing in her diary, and took it from her, reading it aloud. However, she stopped after being angered by its subject matter - it was mostly about Stefan Salvatore.
Ms. Halpern stopped one lesson for a moment after Elena arrived late, looking at her before continuing the lesson and writing on the blackboard. The class was interrupted by Elena and Meredith Sulez, who were discussing the police's search for Stefan. Elena left the class, with both Ms. Halpern and Meredith calling for her to return to the classroom. This was most likely how Caroline Forbes became aware of Elena's journalling.