She could at least tell her daughter that "progressives, leftists, liberals, radicals, etc. don’t “cancel” things--we critique them, we protest them, we may even boycott them, get companies to not support things or promote things or carry them on their station, but reality doesn’t give us the power “to cancel” even if politics did. “Cancelling" and "cancel culture" is what conservatives, white supremacists, and fascist extremists label critiques and protests made by people who care about equality and social justice.

Your friends are making themselves conservative stereotypes of social justice activists by saying they are “cancelling anything, and are missing the context of the terminology, an easy mistake when you haven’t had a chance to study things for a lot of years. So be sure to look up new terms, and at least use wikis to get more context to every issue so you have the history to go with these important issues you are rightly caring about. Remember your friends are just learning too--we all are. Always question, question, question, even your smartest friend."

This is how you encourage her learning to nuance and not walk thoughtlessly in lockstep with any group.