I also don't want to destroy her faith as everyone has freedom of religion and conscience
I'm do not see the connection. Showing her information and letting her draw her own conclusion is not encroaching on her freedom of religion and conscience. Her faith is misfounded if facts will destroy it. Her freedom is being stifled by belonging to a religion does takes away her freedom to hear opposing points of view.
I have received emails from people that had their children die because they refused them blood. After such tragedy, they came to realise they had been misled, and their children died as a result. I think every parent would like to know that they are doing the best thing to protect their child and having information withheld from them is worse than having your faith confronted.
I am not suggesting you rock the boat, but don't hold back because you think it is the honorable thing to do. Hold back if you think it is required to keep your family together.