I'm safe - keeping under insured does have its advantages.
It really sounds as if she is struggling with the reality of her husband and the religion on which she has based her life. I was asked once (while still under fundie delusional) if I would prefer my Mormon boyfriend of fundie friend die and guess who I chose. The fundie because I knew his 'soul' was safe. It is a strange thing that religion can do to ones brain, but it may be possible she was having a moment of weakness about her faith.
Before people get pissed at me, I'm not agreeing with it or the idea, I'm just trying to look at it from her perspective with the consideration that she knew what you had was not life threatening - it seems she may have been wanting comfort that she was doing the right thing by ignoring the 'unequally yoked' part of her belief. It may not hurt to find out with whom she's been discussing your marital divide.
Your wife is certainly not a very clever person otherwise she wouldn't have told you that. And unclever persons are good partners. I think She did that out of love for you. If my wife would have said that I would have smiled and loved her more.
Dude, I really sympathize with your situation. The one refuge I have when I get all spun up about religious insanity is the fact that my wife and I can talk openly about it and be on the same page. I've told her many times that I would go completely insane if she and I didn't see eye-to-eye on being atheists together. I don't envy you.
Obviously this is just a single snapshot into your relationship with your wife, but the part that's most troubling to me is the fact that she genuinely thinks you would end up in hell if you died from either of your medical conditions, and yet she prayed for it anyway. If I loved someone, and I truly thought their eternal soul was in imminent danger, I would be absolutely pleading with God to give them more time so they could still be reached. Even if I wasn't "meant" to be with them, I still wouldn't wish eternal torment on them just to avoid being "unequally yoked," especially if I thought there was a chance they could be saved.
What do you want to see happen with this relationship?
Honestly, I personally wouldn't waste my short life dealing with this nonsense. Take it with a grain of salt because I am just a random person on the internet..but really? She thinks and behaves like this? Does she have redeeming qualities that make the marriage worth it to you?