Mrs. Mackelroy appears in The Ugly Truth as Greg's new math teacher. Her math class came right after Physical Education, and she didn't like the sweaty smell of her students in the classroom, so she complained to the school principal about the situation. The principal then made the students take showers after Phys. Ed. She also used to teach Kindergarten.
- Diary of a Wimpy Kid: The Ugly Truth (First and only appearance)