Our stories are so similar Sanchy. I remember trying to gently reason with my wife only for things to morph into an emotional argument right in front of our toddler. If I could give one piece of advice for now, it's this:
Your wife is pregnant. She's already under tremendous stress, discomfort and her emotions are likely to be flying all over the place. You need to focus on having that baby safely. It's not a good time to put your wife under any unnecessary stress or anxiety right now. After the baby has been born and she has recovered then you can continue to ask questions and shape her towards a future marriage life that isn't controlled by the capricious edicts of an American sect.
Congratulations on a soon to be new member of your family and thanks for sharing your story!.
P.S. Tim Drake 1914's advice on page 1 is pure gold!