I have been entering the baptismal records of St. Joseph church into a searchable data base and it got be wondering about who can be a sponsor. Not surprisingly, there are canon laws:
Can. 872 In so far as possible, a person being baptized is to be assigned a sponsor. In the case of an adult baptism, the sponsor's role is to assist the person in Christian initiation. In the case of an infant baptism, the role is together with the parents to present the child for baptism, and to help it to live a Christian life befitting the baptized and faithfully to fulfill the duties inherent in baptism.
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;
§2 A baptized 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.