Br. Rich SFO:
Yes the Canon Law has always been there and still applies. The fact that you had a disqualified Confirmation Sponsor does NOT in any was invalidate your Confirmation. At this point nothing needs to be done.
This Code of Canon Law has had “the force of law for the whole Latin Church” since the first day of Advent, 1983. (John Paul II, Apostolic Consitution Sacrae Disciplinae Leges).
Before then parent sponsors for confirmation were clearly permitted. According to the General Introduction to the Rite of Confirmation, (dated 22 August 1971):
"5. As a rule there should be a sponsor for each of those to be confirmed. These sponsors bring the candidates to receive the sacrament, present them to the minister for the anointing, and will later help them to fulfill their baptismal promises faithfully under the influence of the Holy Spirit whom they have received.
In view of contemporary pastoral circumstances, it is desirable that the godparent at baptism, if available, also be the sponsor at confirmation. This change expresses more clearly the link between baptism and confirmation and also makes the function and responsibility of the sponsor more effective.
Nonetheless the option of choosing a special sponsor for confirmation is not excluded. Even the parents themselves may present their children for confirmation. It is for the local Ordinary to determine diocesan practice in the light of local conditions and circumstances."
(From The Rites Volume One, Liturgical Press, 1990, ISBN 0-8146-6015-0, page 480).
Did the 1983 Code of Canon Law intend to change this permission for parents to be sponsors? I am unsure, but here are arguments that there is no such intention:
The wording of canon 874 §1 5°, is “not be the father or the mother of the one to be baptized.” So there is an explicit link to baptism, perhaps highlighting that this does not apply for confirmation. So by referrring to canon 874 in canon 893 §1 the intention and understanding may have been that canon 874 §1 5° not apply.
According to canon 846: “The liturgical books approved by the competent authority are to be faithfully observed in the celebration of the sacraments.” So if the liturgical book for confirmation has not been changed, then the 1971 General Instruction would seem to have force.
Given this uncertainity a case can be made that it is reasonable to follow the decision of the diocesan bishop on whether parent sponsors for confirmation are allowed.