The emphasis on spiritual mentorship in the LDS Church is similar to that in the more "low-church" traditions of Protestantism, with a stronger emphasis placed on the husband and father of a family to provide spiritual guidance for all of his family, ideally in consultation with his wife, even if the husband is not a member of the LDS Church, based on interpretatios of certain Biblical texts which proclaim the spiritual authority of husbands in marriage.
Who is expected to lead the family in spiritual mentorship?
the husband and father