What does Mrs. Granger do to try to stop "frindle" from becoming a word, in Andrew Clements' book Frindle?

In Andrew Clements' Frindle, to stop
"frindle," Mrs. Granger first tries to explain that it cannot be a word because it has
no meaning. Next she threatens the students who use the word. Each student has to stay
after school and write 100 times that they are writing the assignment with a
pen. (Some of the students get creative and start substituting the
word "frindle" instead of "pen." There is a contest among them to see who can get away
with it the most times.) One afternoon, there are so many kids after school that they
cannot fit in Mrs. Granger's classroom. Mrs. Granger also puts up a poster warning
students about using the word.

There are two ironies. The
first is that by trying to "contain" the word, it gets used more and more and spreads
throughout the country. The second irony is that ten years after the "frindle" frenzy,
Nick gets a letter that he had sealed, which Mrs. Granger had
written to him when the "war" of the words took place. Inside Mrs. Granger explains that
she was rooting for him the whole time, but played the villain because she believed it
would help the word to grow.

Mrs. Granger loves language.
Nick invents a word to test Mrs. Granger's theory about who controls what words are used
and placed in the dictionary. Mrs. Granger covertly helps Nick realize that he (and
others) can be those people who use words and that
their use decides which words make it into the dictionary. Mrs.
Granger admits that she was a little aggravated at first, but later she was in complete
support of what Nick was doing.