Was Scout's first grade teacher, Miss Caroline, upset because Scout could read and write?
Yes. On the first day of school Miss Caroline wrote the alphabet on the board and asked Scout to recite it. After Scout recited the alphabet, Miss Caroline made Scout read from the book My First Reader and the stock-market quotations from The Mobile Register (1.22). Miss Caroline told Scout to tell her father not to teach her how to read anymore because Miss Caroline believed that it was best to start reading with a fresh mind. Later on in the school day, Scout begins writing a letter to Dill because she is so bored with the lesson. Miss Caroline catches Scout writing a letter and tells Scout to tell her father to “stop teaching her.” The reasoning behind Caroline’s disapproval stems from the fact that first graders print, and third graders write. Scout is tremendously upset following Miss Caroline’s interventions, and begins to hold a grudge against Calpurnia for teaching her how to write.