The Sacrament of Confirmation: Canon Law

In a little over a week's time, I will be attending the Confirmation of my eldest niece, for whom I am sponsor.  I thought a refresher on the sacrament of Confirmation might be in order for me.  I'll do this in three parts:  first, Canon Law; second, the modern Catechism (and its Compendium); third, the Catechism of Trent.

Canon Law, 879-896 (excerpts)

Can. 879. The sacrament of confirmation confers a character. By it the baptised continue their path of Christian initiation. They are enriched with the gift of the Holy Spirit, and are more closely linked to the Church. They are made strong and more firmly obliged by word and deed to witness to Christ and to spread and defend the faith.

Can. 890 The faithful are bound to receive this sacrament at the proper time. Parents and pastors of souls, especially parish priests, are to see that the faithful are properly instructed to receive the sacrament and come to it at the opportune time.
Can. 892 As far as possible the person to be confirmed is to have a sponsor. The sponsor's function is to take care that the person confirmed behaves as a true witness of Christ and faithfully fulfils the duties inherent in this sacrament.

Can. 893 §1 A person who would undertake the office of sponsor must fulfil the conditions mentioned in can. 874.

§2 It is desirable that the sponsor chosen be the one who undertook this role at baptism.[!]

(Can. 874 §1 To be admitted to undertake the office of sponsor, a person must:

1° be appointed by the candidate for baptism, or by the parents or whoever stands in their place, or failing these, by the parish priest or the minister; to be appointed the person must be suitable for this role and have the intention of fulfilling it;

2° be not less than sixteen years of age, unless a different age has been stipulated by the diocesan Bishop, or unless the parish priest or the minister considers that there is a just reason for an exception to be made;

3° be a Catholic who has been confirmed and has received the blessed Eucharist, and who lives a life of faith which befits the role to be undertaken;

4° not labour under a canonical penalty, whether imposed or declared;

5° not be either the father or the mother of the person to be baptised.

§2 A baptised person who belongs to a non-catholic ecclesial community may be admitted only in company with a catholic sponsor, and then simply as a witness to the baptism.)