If you are intent on marrying a cult member against all better judgement then expect to spend the rest of your time with her being the target of cult indoctrination and being expected to join.
Any children you have will also be the targets of cult indoctrination and be expected to join. That is without the the chance of dying from the blood issue, having their childhoods stolen and messed up by being brought up in a cult. They wont thank you for it one little bit.
The only way this will work is if she is willing to research her religion and see that it is a cult and then leaves it truly and firmly behind her.
If she isnt willing to even research her own religion (she doesnt know it's a cult yet) or even read on a forum like this one, then you have no hope at all, use that point as a wake up call to your self and walk away from this madness.