Why does Miss Caroline disapprove of Scout's reading ability in To Kill a Mockingbird by Harper Lee?

is a
little fearful about her first day of school in , by , and it turns out she
was right to feel that way. Her teacher is Miss Caroline, and she seems quite harmless at
first:

Miss Caroline was no more than twenty-one. She had
bright auburn hair, pink cheeks, and wore crimson fingernail polish. She also wore high-heeled
pumps and a red-and-white-striped dress. She looked and smelled like a peppermint drop. She
boarded across the street one door down from us in Miss Maudie Atkinsons upstairs front room,
and when Miss Maudie introduced us to her,was in a haze for days.

Unfortunately, Miss Caroline was taught how to teach a certain way and to a certain
kind of students (which is clearly not what this group of students is), so she does not quite
know what to do when something does not go according to her perfectly thought-out plan. Scout
already being able to read is one of those things.

As Scout begins to read,
"a faint line appeared between [Miss Caroline's] eyebrows," and when she
"discovered that [Scout] was literate and looked at me with more than faint distaste. Miss
Caroline told me to tell my father not to teach me any more, it would interfere with my
reading."

This, of course, is a ridiculous notion. Scout tries to
explain that she was never taught to read at all; she simply sat on her father's lap and, over
time, she learned. Scout says,

Miss Caroline apparently
thought I was lying. Lets not let our imaginations run away with us, dear, she said. Now you
tell your father not to teach you any more. Its best to begin reading with a fresh mind. You
tell him Ill take over from here and try to undo the damage-

Maam? 

Your father does not know how to teach. You can have a
seat now.

Miss Caroline is clearly not flexible and does
not know what to do when things do not go as planned. She is proof that book knowledge is quite
different than real-life experience. The truth is that she should have been thrilled that one of
her students can already read; instead she is horrified and commands Scout to stop reading until
Miss Caroline can teach her. Another ridiculous notion. 

Miss Caroline watched the class file out for lunch. As I was the last to leave, I saw
her sink down into her chair and bury her head in her arms. Had her conduct been more friendly
toward me, I would have felt sorry for her. She was a pretty little thing.