Hey Marcos,
I would dial back the "persecution", and quick. The others are right, you don't want to let your family get knee-deep in this stuff, but you also don't want to unwittingly push them into it. Jesus said family members would turn on his followers, that they would be persecuted. By resisting your children's learning, you are providing a "fulfillment" of that prophecy.
This isn't advice, just brain storming. What if you study *with* her? Give it an honest evaluation. Don't come off all 'look here' and 'see, this is bunk', but just ask subtle questions. Not obvious stuff like, "Where did Cain get his wife?" (married an aunt, or a sister) but more poignant things like "Why would God listen to and answer a prayer offered by ten people, but not by one person?" (Paul asked people to pray for him, was Jehovah unwilling to help him based on his own prayers? Why?)
Studying yourself would also give you more leverage with the kids. "As the family head, the spirituality of my family is my responsibility," you could sincerely state, "I need to see for myself that this is the right religion to teach my kids before I can allow them to be taught it."
There's not going to be any easy answers here. But it's a sure bet that if you put up a big fight, you'll just be labelled an 'opposed unbelieving husband', she'll be talked to by others sisters in the hall that have unbelieving husbands, and she'll believe she's enduring your persecution for Jesus.
So, Everybody, What can Marcos do to help his wife see the fallacies of the org without coming off like a pawn of Satan?
Dave