A discussion took place as to the proper age at which deceased children should be endowed in the Temples after attaining to the age of eight years. The rule established by Pres[ident]. Brigham Young at the opening of the St. George Temple was that such children might be endowed at or near the age of fifteen; but this had been departed from in the Logan Temple, where Pres[ident]. [John] Taylor had fixed the age at 8 years. It was Pres[ident]. Woodruff's view that the rule in the Logan Temple should conform to the rule established by Pres[ident]. Young in relation to this matter and which was observed in all the other Temples in Zion. This became the sense of the meeting.
An informal talk followed on the subject of the age of spirits before they appeared in the flesh. The idea conveyed was that all spirits before appearing in the flesh are of adult age, and that after the death of the body they appear in their natural adult size; but that such spirits, if death occurs in childhood, again enter the child bodies, which grow to the full stature of their spirits after the resurrection.
[Source: First Presidency and Quorum of the Twelve minutes]