Brian C. Hales writes on the ultimatum Joseph gave to Lucy Walker.
Brian C. Hales, Joseph Smith's Polygamy: History and Theology, 3 vols. (Salt Lake City, UT: Greg Kofford Books, 2013), 1:484
27. The only known plural proposal that contained a time limit was issued to Lucy Walker who was introduced to the principle by Joseph Smith in 1842. She subsequently agonized for many months as the Prophet patiently waited. Lucy related: "I was tempted and tortured beyond endurance until life was not desirable. Oh that the grave would kindly receive me, that I might find rest....Oh, let this bitter cup pass. And thus I prayed in the agony of my soul. The Prophet discerned my sorrow. He saw how unhappy I was." Lyman Omer Littlefield, Reminiscences of Latter-day Saints: Giving an Acount of Much Individual Suffering Endured for Religious Conscience, 46. Only after witnessing her turmoil and having waited a minimum of several months, in May of 1843, Joseph instructed Lucy: "I have no flattering words to offer. It is a command of God to you." Then he gave a singular directive, "I will give you until tomorrow to decide this matter." This twenty-four-hour time limit is sometimes quoted to assert that Joseph gave ultimatums to his potential plural spouses to quickly press them into compliance. See, for example, George D. Smith, "The Forgotten Story of Nauvoo Celestial Marriage," 157. In reality many months passed between the two events.