If she's 14, she's old enough to understand.
Take your time ! when I first mentioned the Kikes and their holo-hoax, my brother was shocked (growing up brainwashed) but I asked him (rhetorical) questions, showed him photographic evidence, he slowly became more and more aware of the world around him.
Take baby steps, otherwise you may frighten your sis. People need time to wake up. As for your parents, I had the same problem with mine : but keep on meditating, it will take time, but you will succeed with patience
Heil Hitler
hail Satan