I am very aware of the sources on this subject. It is indeed fascinating. And sacred. I don't post too much about it, though I am happy to read, collect, and ponder all I can. My point is merely that an ordinance, even this one, does not assure exaltation. The only thing that can--ultimately--is God. (cf. JST Gen. 14:25-40). It cannot come by the will of man, only by the will of God. Therefore, even if a man, such as the President of the Church, were to desire to give it to a loved one, without the seal of heaven it is of no force.
I think Joseph's explanation of this dual-nature of the sealing is as inspired and thorough as can be: "The more sure word of prophecy means a man's knowing that he is sealed up unto eternal life, by [1.] revelation and the spirit of prophecy, [2.] through the power of the Holy Priesthood [the ordinance]" (D&C 131:5). Both the revelation and the ordinance are required. And I don't think it matters in which order.
In Emma's case, we know the date of the ordinance (thanks to Ehat's research). Whether she has or will receive the seal of the Holy Spirit of promise (cf. D&C 132:19) is the question. I'd like to give her the benefit of the doubt, but it also would not surprise me if she had not qualified for the blessing in mortality (thank goodness that's not the end of our story). Her struggle with plural marriage gives me pause. It was why Joseph waited so long to finish restoring the temple ordinances.