I have observed in the past that of course the Holy Ghost will dwell with little children just as it does with any member who was been given the gift of the Holy Ghost, for what is more pleasing to God than innocence, and what is more innocent that our little ones? How could the Holy Ghost be refrained from visiting such perfect purity? How could the savior say "of such is the kingdom of Heaven" while the Holy Ghost was unable to dwell with them?
Obviously, when they reach the years of accountability this necessarily changes unless they receive baptism for the remission of sins and receive the gift of the Holy Ghost.
But some will say it doesn't square with our doctrine that a child can have the Holy Ghost dwell with him just as someone with the gift of the Holy Ghost. And to them I would reply:
Luke 1:13 But the angel said unto him, Fear not, Zacharias: for thy prayer
is heard; and thy wife Elisabeth shall bear thee a son, and thou shalt
call his name John.
1:14 And thou shalt have joy and gladness; and many shall rejoice at
1:15 For he shall be great in the sight of the Lord, and shall drink
neither wine nor strong drink; and he shall be filled with the Holy
Ghost, even from his mother's womb.