Sandra Tanner does not speak for Mormons, she is hostile to the LDS church and misrepresents their teachings. Her former membership does not validate her views of the what the LDS Church believes when she is deliberately misstating those beliefs.
What about all the other people who have left the LDS church are they not experts on the matter? Why is it when someone reports to a belief or ritual that the LDS partake they are immediately discounted as antagonist like that is a bad thing?
Of course she is an antagonist she left your church and is trying to enlighten people on its false doctrine. How is she wrong when she quotes from the Book of Mormon and from information written by active Mormons? Are your own people wrong?