Sorry to hear this - I've been somewhat indulgent in listening to both sides too, but have been pushed further to the left by the carelessness of right-wing media regarding vaccines. The worst part is that it becomes almost like a religious belief - you can't reason someone out of this if all the "news" they're taking in is telling them the same thing. The only thing I can suggest is appealing to emotion by somehow having her exposed to
people who regret making the choice to avoid vaccines.