Dear Gramps,
Can a mortal woman and a resurrected man have children together? If a man dies and his wife lives into the Millennium, can they have children following his resurrection?
J

Dear J
Only mortals will have the ability during the millennium to procreate. Mortals living during the millennium will pass from mortality to immortality in the twinkling of an eye—

And he that liveth when the Lord shall come, and hath kept the faith, blessed is he; nevertheless, it is appointed to him to die at the age of man. Wherefore, children shall grow up until they become old; old men shall die; but they shall not sleep in the dust, but they shall be changed in the twinkling of an eye (D&C 63:50-51).

Thus a mortal strain will propagate itself until the end of the millennium. This is necessary since the great work during the millennium will be to perform all of the saving ordinances of the gospel for all of our Father’s children who will have lived on the earth from the beginning of man until the coming of the Lord, and who would desire to align themselves with the kingdom of God, but did not have the opportunity to do so during the period of their mortal lives. Since all of the saving ordinances are designed to be done in mortality, resurrected beings must have mortals act as proxies for them to perform the saving ordinances in holy temples that will dot the earth during the millennium.
The only others in the eternities who will have the ability to propagate their posterity will be those who will have achieved the status of exaltation in the celestial glory. Only those who are married for time and eternity by the power of the holy priesthood during their mortal sojourn and who honor their marriage covenant by living by every word that proceedeth forth from the mouth of God (D&C 84:44) will be exalted. They will continue to bear children, but their children will be composed of spiritual material in exactly the same sense that we were when we were born as spirit children of our Father in Heaven.
So there are only two periods during your mortal existence when you will be able to bear children–as a mortal with a mortal companion and as an exalted being the celestial kingdom after the resurrection.
Gramps