Mrs. Lowry (known as Mrs. Borners in the online version) is a teacher who appears in Diary of a Wimpy Kid: The Last Straw.
When Greg fell asleep in Mr. Watson's class, Mr. Watson punished him by forcing him to sit in the front of the classroom. However, Greg fell back asleep and did not wake up until the next period. The period was taught by Mrs. Lowry, and she gave Greg his first detention.
In the online book, Greg is instead given detention by Mr. Peters (known as Mr. Watson in the book version).However, she still makes an appearance and plays the same role regardless of giving Greg detention as in the book version.