In Freak the Mighty, is school different for Freak the Mighty after Christmas vacation?

The answer to your question comes in chapter 21 of the book, which is entitled "An Accident of Nature." After Kevin and Max escape from "Killer Kane," Max's father, and are responsible for him getting caught by the police, the pair become local celebrities. They get their pictures in the local newspaper, and they are featured on local TV. Max says that their classmates are jealous of the attention they're getting. Their teacher, Mrs. Donelli, calls them the 'dynamic duo' and posts their pictures on a bulletin board in her classroom. Some of their classmates draw mustaches on their pictures. Kevin thinks he looks good with the mustache and tells the teacher to leave the picture up. Max just wishes all the attention would go away.
Max is also thinking about the upcoming trial and the fact that he will have to testify against his father in order to keep him locked up. The quests of Freak the Mighty started out small, with small acts of bravery. Encountering Max's father was a true test of bravery for both of them. Kevin and Max came out of that with a deeper bond and more maturity. They are a great team but still retain their individual personalities.

After Kevin rescues Max and Killer Kane is thrown in jail, the boys return to school, and the atmosphere around the school is drastically different. The two friends have become locally famous for their brave exploits over Christmas break and begin receiving positive attention from their teachers. Max mentions that everyone in school is jealous of him and Kevin because they got their names in the local newspaper. Max also says that Mrs. Donelli posted their picture from the newspaper on the bulletin board and began calling them the "dynamic duo." Max and Kevin are not used to being the source of envy among their classmates, and Kevin seems to enjoy the attention. Despite the fact that one of their classmates drew a mustache on their posted picture, Kevin makes Mrs. Donelli leave it up. In contrast, Max mentions that he hates the extra attention and wishes to forget about the whole situation as soon as possible.