Many Mormon girls place the cart before the horse. But I'm still going to show up, even if it means I lose an hour or two of sleep. My husband is a medical student, so I have a few years until I'm a "doctor's wife. Every bishop, new set of missionaries, home teacher, etc.
So it is going to be over anyway. I don't know if it's worse for us: For me, it's been an inner battle with myself, should I follow my husband or should he follow me as I am one year ahead. He doesn't like to complain or talk about work too much when we're together so it really helps to hear from another resident just how crazy it is. The goal of dating at that age is to broaden your social circle and learn more about yourself. My Buddhist husband likes Mormons and even going to church. I'm pointing this out because I don't know her and couldn't tell you what to expect. Don't forget too that IF you are successful in turning the lights on and deconverting her, the family would resent you the rest of their lives.
Catholics basically married catholics and protestants basically married protestants. I let things slide often not thinking it is worth a battle. In a few months, he will begin working, and his first few years will be demanding what else is new. You will be able to best gauge where her beliefs stand in regards to the church if you listen to how she describes her mission. Too many disappointments, sick nights without your husbands, his absence during family gatherings, my usual OBGYN checkup without him, even simple things of hugging and spending quality time is always remote. He is in a way to become a Ex mormon. I wouldnt encourage my kids to date a mormon. The important thing is that you are getting to know one another, not that you are always doing fancy things. Ultimately there are no guarantees but I'd say it's worth a shot. No sex before marriage.
I think in most situations its either you join or she leaves- either you, or the church. God told me to marry my husband. But, if ever were there were a time to be overly cautious it's with this topic.