As for the liturgies, the catechumenate for children will look much like that of adults:
253. The Christian initiation of these children requires both a conversion that is personal and somewhat developed, in proportion to their age, and the assistance of the education they need. The process of initiaiton thus must be adapted both to their spiritual progress, that is, to the children’s groth in faith, and to the catechetical instruction they receive. Accordingly, as with adults, their initiation is to be extended over several years, if need be, before they receive the sacraments. Also, as with adults, their initiation is marked by several steps, the liturgical rites of acceptance into the order of catechumens (RCIA 260-276), the optional rite of election (RCIA 277-290), penitential rites or scrutinies (RCIA 291-303), and the celebration of the sacraments of initiation (RCIA 304-329); corresponding to the periods of adult initiation are the periods of the children’s catechetical formation that lead up to and follow the steps of their initiation.
Children are held to a similar, but not a standard identical to that of adults. Before baptism, a child will have been discerned to have some growth in the life of faith. How much? That answer would be relative. It would seem that the Church can ask more of a teen than a six-year-old. Later in this section, we’ll read of the recommendation that child catechumens associate with those of their own age.
It would seem difficult to reconcile the short periods of preparation/catechesis through which we steer parents with a preparation period lasting “several years” for a child catechumen. Having seen many parents bring older children for initiaiton, I can attest that a catechumenate which lacks the summer months isn’t quite strong enough to imprint patterns of worship on some families.
Curious, but not surprising, that the celebration with the bishop is optional.