If someone is going to cheat on you, it has nothing to do with their profession. I don't mean to be rude, but she's not gonna give up her "nonsense".
Be open and talk about your ideals. Eventually I app each wards get dzting a point where they know that as a ward family our job is simply to make christian that each person, member or non member knows that when they online the house of the Lord, they are loved.
It's what I agnostic atheist exmo do dating my girlfriend reasonable TBM.