Today she pulled me aside and said that she disagreed with what I had to say. I asked why and she said that she believed what defectors had wrote in their biographies (she didn't name any specific books). I didn't actually get to counter that (or respond to anything really) beyond the documentary (Loyal Citizens of Pyongyang) I linked in my email which she didn't watch apparently. She was respectful I guess. Should I respond with a critique of Escape from Camp 14 and In Order to Live or should I just brush it off?
I would let it go if I were you. This is still January, and you're still stuck with her for at least 5 months. That's almost half a year. She probably didn't watch it because she's overworked like most teachers. At best, she's just humoring you like a child and isn't taking what you're saying seriously and at worst, she's ideologically committed to her position and no dipshit bratty kid is gonna lodge her out of her ideological hole she dug herself in.
I don't how to tell you this without hurting your feelings, but most adults do not take kids seriously and teens, contrary to what pop culture pushes out, are still considered kids by many adults. If your teacher is one of those teens-are-just-horny-kids type of adult, your efforts to deprogram her are a lost cause because once the cognitive dissonance is strong enough, she's just going to default to the "I don't have to take shit from this stupid kid" thought terminating cliche.
This doesn't mean arguing with her was a waste of time. Because your target isn't some cringey millennial/gen x lib, but your fellow classmates. Those are the people you should radicalize. Consider your teacher as a rhetorical punching bag so that when your classmates put rhetorical roadblocks, you can use your experience with your teacher to navigate past them.