Canon law says that anointing of the sick is to be done to someone having attained the age of reason, same as reception of the Eucharist and the Sacrament of Penance.
However, as "Food for the Journey", if a child is near death, do they usually still receive the Eucharist as Viaticum?
If you read the Catholic encyclopedia entry I linked to on viaticum it says that they are. But, I'm not sure if it's outdated because it seems to conflict with Canon Law. As this answer states younger children receiving communion used to be normal, but not any more, is this the same for Viaticum or is it totally separate from the sacrament of anointing of the sick (other than the fact that they both usually take place before death).