In this case it involves a public school.
This is really the ‘crux’ of the issue, especially if you are talking about First Amendment issues and the speech of this teacher and/or students. (I see no indication in the story that a student may have initiated the topic of discussion with a question or a comment.)
I don't agree that the public schools should be off limits to student prayer or a curriculum that includes study of the Bible. The foundation of our civilization is Mosaic Law. The very idea human beings have any individual rights at all not subject to the whims of a monarch comes directly from Moses and obedience subject to commandments from Yahweh.
I don't care for the public schools much. There are a few good ones, they are not all bad as some would say, but most of them have caved in to the cultural Marxism that runs amok in their administration. Santa Claus is no exception.
Now, if the offended, supposedly Christian parents (and even some here) want to crucify this teacher, taking their turn upon her with some sort of vengeance because of some imaginary hobgoblin (a golden calf, a sacred cow) they have erroneously associated with Christmas - - I will say they are no different than those that demanded crucifixion of Yeshua, for whom the holiday (holy day) is so named!
This takes us right back to the fight over the “happy holidays” vs. “Merry Christmas” where the cultural Marxists want to remove Christ from Christmas. I thought this was something people were fed up with. Illogical.
If this teacher, so maligned here in many cases, is guilty of a crime or heresy and should be punished, maybe we should dig up the petrified corpse or summon the ghost of Pontius Pilate and do the whole thing over again of putting Yeshua on trial.
And, if this teacher so believes that she is indeed following the commandments of her omnipotent God, there is no need to defend her, because if, as she believes (and others who may claim to) that God will protect her, there is no power on this earth or temporal human conceit that can condemn her.
Every civil right we have comes from a monarch like person or individuals. When the founders put together the Constitution, it was written by those in leadership. The monarch's of their time. That they were wise enough to include certain civil liberties is wonderful. That they have been skirted, muted and temporarily or permanently taken away throughout our nations history just proves that they do come from individuals.
In addition, simply ask the remaining populations of the world how those rights given to Moses have worked for them.
Yes, for the most part what remains of our morality does allow us to believe in a higher being and the freedoms that were given to Moses. But what God gave to Moses can only be given to us by the power of men. Otherwise, what God gave to Moses would also be enjoyed by the balance of the world. I don't see that as current practice.