Now just ask yourself what are the odds of her thinking her way out that crazy nonsense.
In fact, your GF is probably one of the countless Mormon women who get married only to find out they have zero sex drive because of what they learned growing up.
She is in pretty deep and culture is a powerful force. As the patriarchal leader, it will be up to you to figure it out and to dispel her unrealistic fantasies.
The "loneliness" is not an issue for me.