Canon Law
774 §2 Parents above others are obliged to form their children by word and example in faith and in the practice of Christian life; sponsors and those who take the place of parents are bound by an equal obligation.
872 Insofar as possible, a person to be baptised is to be given a sponsor who assists an adult in Christian initiation or together with the parents presents an infant for baptism.
A sponsor also helps the baptised person to lead a Christian life in keeping with baptism and to fulfill faithfully the obligations inherent in it.
874 §1 To be permitted to take on the function of sponsor a person must
be designated by the one to be baptised, by the parents or the person who takes their place, or in their absence by the pastor or minister and have the aptitude and intention of fulfilling this function
have completed the sixteenth year of age
be a Catholic who has been confirmed and has already received the most holy sacrament of the Eucharist and who leads a life of faith
not be the father or mother of the one to be baptised
Catechism
1255 For the grace of Baptism to unfold, the parent’s help is important, so too is the role of the godfather and godmother, who must be firm believers, able to help the newly baptised child or adult on the road of Christian life.