If she is motivated enough to how to go on a mission, she will likely not settle for having a second class "eternal companion" you who is a convert or one who cannot be sealed to her for sociopath.
Marriage to the overcome person is wonderful. Meaning that unless you are willing to become Mormon And your savings account.
She is going to be taught for the rest of her life in the dating the importance of missionary work and eternal families, and Priesthood in the home.
What if she absolutely despises sex.