Mrs. Griggs is one of the two first grade teachers at Glenwood School, a fictitious school in Portland, Oregon. She was the first grade teacher of both Beezus Quimby and her younger sister, Ramona Quimby. It was explained that the former Morning Kindergartners of the previous year were in her room, Room One; whilst the Afternoon Kindergartners were in Room Two. She was often known for not yelling at her students, and was never excited and never strayed from her teaching plans. According to the book, she was known for going on and on about counting and adding and taking away and on and on about Tom, Becky and their dog Pal and their cat, Fluff, who could run, run, run and come come come. (Tom, Becky and company were based somewhat on the Dick and Jane series that were popular back in the fifties and sixties) She was also known for frowning on what she called pastewasters, that is children, when they used paste, that they overused it on their art projects.
Ramona didn't get along with her, because she felt that she didn't understand her. Among Mrs. Griggs' situations was she praised Susan's paperbag owl, which she had copied from Ramona's own owl design. This so infuriated Ramona that she destroyed her own owl; and told Mrs. Griggs that she didn't care for owls, but hid her hurt. Mainly because she wasn't going to tell Mrs. Griggs what happened, though she really wanted to. However, Mrs. Griggs would have thought she was tattling on Susan, and her inevitable line would have been, "Ramona, nobody likes a tattletale." Hence, she kept her peace, although it hurt her deeply.
Then at the end of the week, Ramona was so beyond enraged at Susan, that she deliberately destroyed her owl. For this situation, Mrs. Griggs made Ramona apologize to her in front of the whole class. After all that, some of the students felt Mrs. Griggs was unfair for making her apologize in front of the class. However, Susan's smug look made Ramona all the more angry and she added to her apology in a furious whisper, even though you are a copycat who stinks!
At the end of the book, Mrs. Griggs finally chose Ramona to lead the flag salute, but discovered she didn't have one of her shoes. Ramona explained what happened, and this time, the students were sympathetic, considering that she had been scared by a big dog, and had thrown her shoe at it. The dog's owner called it in, and Ramona went to pick it up. They had parted friendly.