How does Mrs. Granger feel about the word "frindle"?

In the novel Frindle, a fifth-grade language arts student named Nick wants to upset his teacher, Mrs. Granger. Known as a smart kid but a troublemaker in the classroom, Nick comes up with a plan. He approaches his teacher and questions her about the meaning of words in general. He decides to change the name for a pen and creates the word "frindle."
Mrs. Granger objects in an outright manner to his tactics and decides that changing the name of the word "pen" is not acceptable. She appears to be a very strict teacher and is unwavering in her classroom rules. Yet, the more she objects, the more popular "frindle" becomes. With the help of a businessman to market the word "frindle" and a journalist who reports the news, Nick becomes famous all over the country.
Ironically, in the end, neither Nick nor Mrs. Granger turn out as a reader might have expected. The formerly disruptive student, who is turning twenty-one, uses some of his business profits to "give back" to his elementary school by donating a million dollars. After Nick becomes famous, Mrs. Granger interestingly states that she disagreed with Nick’s use of the word "frindle" because she knew that it would become popular and powerful if she strongly objected to the name change. It looks like the teacher knew what she was doing all along.

In Andrew Clement’s first novel, Frindle, a fifth grader named Nick Allen creates a new word for “pen” to challenge his new teacher, who has a reputation throughout the school for being strict and is not well-liked by the students. Now calling all pens by the name "frindle," Nick must deal with the newfound popularity of the word amongst his classmates while also contending with Mrs. Granger, who outwardly dislikes the word and goes as far as to punish students for using it.
Eventually, the popularity of the word begins to spread, and "frindle" becomes known throughout the country, which makes curtailing its use in Nick’s school impossible.
The story ends with Nick as an adult. He has become wealthy due to the popularity of the word frindle. He receives a letter from Mrs. Granger in which she explains that she was hostile to the use of his new word because she knew her opposition would increase its popularity.