Gary James Bergera identifies May 28, 1843 as sealing date for Joseph and Emma Hale Smith.
Gary James Bergera, "The Earliest Eternal Sealings for Civilly Married Couples Living and Dead," Dialogue: A Journal of Mormon Thought 35, no. 3 (Fall 2002): 53–54
Before the end of the next month, Emma Smith and her husband's older brother, Hyrum (who also served as presiding patriarch), finally, according to Clayton, "received the doctrine of priesthood" (that is, plural marriage). Hyrum's conversion was total; Emma, though she had participated in the May 1843 resealings of sisters Emily and Eliza Partridge to her husband, was less enthusiastic. As a reward for Emma's cooperation, she and Smith were eternally sealed on 28 May 1843, the church's third such union. Also sealed were Mormon stalwarts James and Harriet Denton Adams (m. 1809). Both couples were sealed during a meeting of Smith's Quorum of the Anointed, scene of the earliest endowment ceremonies. Emma and Harriet, the first women to witness the quorum's activities, would be initiated as full members later that fall. Quorum members accepted Smith's doctrine of plural marriage in theory, if not yet in fact. By the time of his sealing to Emma, Smith had married some twenty-five celestial wives, and the following brethren had, with Smith's permission, taken at least one plural wife: Reynolds Cahoon, William Clayton, William Huntington, Orson Hyde, Heber C. Kimball, Vinson Knight, Joseph Bates Noble, Willard Richards, Brigham Young, and Lorenzo Dow Young.