Respect invites us to remember that people have a reason for what they believe.
Some inherit atheism from their families or cultures.
Having some knowledge of what people believe is pretty valuable. Will she insist that your children be raised in her faith tradition?
But a growing number of people (especially young people) are “nones”, so having exposure to that is valuable, too. You need to have these conversations before the relationship gets serious, or RIGHT NOW if it already is.
As an adult, I'd place my hand on the outside of the plane while boarding and pray that the "sacred blood of our Lord Jesus Christ" would protect the plane and passengers -- and I believed with my whole heart that it would work (since I haven't been involved in a plane crash, I guess it did). I abandoned all thoughts of God in my twenties, until it became clear that I needed to be sober.