If she is actually "religious" in the overt sense, I would say stay away. Religious folks at that extreme will eventually need to chose between you and their faith at some point, to some degree or another. However...
In my experience with Catholicism, very few are like that. My wife's family is Catholic, (she herself is agnostic), and they are very accepting of the fact that neither of us are believers, (including a BIL who is a former Vatican priest). I really don't know of any modern Catholics that have such a polarized worldview. They tend to view most of their religious rites more as family tradition, than actual requirements to be "saved".
All religion is toxic, but this one in modern context, is a good deal less than most.
d4g