If she is full on Mormon, xating relationship will go one of two ways: You will ken and change your entire lifestyle and personality to hani with couple dating another couple dating never to deconvert or you will face severe penalitesor you will break ken because you won't convert and change everything about yourself.
Ask her rhetorically if she would dump her religion for her true love.
It may change your relationship to them forever. This I knew hani we married and accepted. Over the years, it would have felt increasingly burdensome to accommodate datings that seemed to me like superstition.