Generally speaking, when a teacher asks this kind of question, they are asking the student to explore how a particular character is dynamic. Dynamic characters change over the course of the story, and the changes are often internal personality changes. Dynamic characters are different from static characters, who remain unchanged by the events or people that they come into contact with during the story.
In Lewis Carroll's Alice's Adventures in Wonderland, Alice is a static character. She reacts to the environment around her: it scares her, delights her, and makes her curious. It However, Alice is never fundamentally shaped or changed by her adventure. The story ends with Alice waking up and resuming her life as it was before. She remains unchanged despite all that happened to her.
It is possible that this particular question isn't looking for the standard "literature teacher" answer that explores static and dynamic characters. The question simply asks how Alice changed in the book. In that case, a reader can confidently say that Alice did change in the book because she physically changed. Alice consumes different items that cause her to shrink and grow in size. The changes to her physical shape are fun to read about and serve to get her into and out of trouble.