Confirmation is not the candidate confirming his/her faith as an adult.
The name Confirmation does not come from this act or the renewal of the candidate’s baptismal vows. Rather, the name comes from the fact that the celebrant, normally the Bishop, as the head of the local church diocese has come to “Confirm” the baptism of the candidate (i.e. complete the other side of the Baptism/Confirmation relationship).
More specifically, just as with other sacraments, the ultimate power and action for the sacraments is not something that resides within the celebrant, but it is God who acts through sacraments (i.e. they are efficacious signs—they do what they are).
Confirmation is not a sacrament of maturity
Again, we should remember that the emphasis in sacraments is on what GOD does and not on what the child is or is not doing. God is not “Confirming” the maturity of your child. Rather, this sacrament, as a sacrament among the three sacraments of initiation, is welcoming your child into full membership in the church with the two-fold action of Baptism/Confirmation marking them as a Christian for a particular purpose. The fullness of this welcome is made complete by the invitation to share in the Eucharist now and from now on as a fully initiated member of the church.
Confirmation is not the third sacrament after communion
Confirmation is one of the 3 sacraments of initiation whose original order is Baptism/Confirmation, Communion. Think of this restored order as entering into the waters of Baptism, coming out of the Baptismsl waters into the embrace of Confirmation (Laying of Hands, Anointing with Chrism, Sharing the Sign of Peace), being welcomed to the table (for Communion). Or in secular terms, like preparing to go out: washing, putting on new clothes and perfume/cologne, and going out to a meal. It is not simply the “next sacrament” in a series of sacraments that count us up from 1 to 7. Although you or your child may have experienced baptism as an infant and the other two sacraments of initiation sometime later, with Communion celebrated before Confirmation, you should still think of these three sacraments as going together to form a fully initiated Catholic, a member who has been washed clean, commissioned in the Spirit as a disciple to act in the world, and sustained by the Eucharist on the way to the Kingdom.