Religion taugh in schools vs First Amendment rights

After reading about certain activity proposed at a public school, I realize more fully when there is reasonable grounds to restrict first amendment rights.  I read of a school wanting to reenact the persecution of the Jews during the Nazi reign wearing yellow stars.  These symbols are not appropriate school and would not be right to be used outside of the particular class doing the simulation.  They could use less tolling symbolism, like wear some blue dot or such, and not risk bringing up the terrible memories of the mass murder and torture of the holocaust.  I think that I would not allow a school to do this were I to have an authoritative position.  I feel that it would be counterproductive to the education of those participating and would promote exclusion.  These cases are those when I am okay with a restriction on freedom of speech.