Requirements for Confirmation Sponsors:
The Code of Canon Law (Church Law) specifies the requirements for
serving as a sponsor at Confirmation (Canon 893) are the same as those
for godparents at Baptism (Canon 874): a sponsor may not be the parent
of the person being confirmed, a sponsor must be at least 16 years old, a
sponsor must be fully initiated (Baptism, Confirmation, Eucharist) in
the Catholic church, a sponsor should live a life of active faith in the
Catholic Church, and if married a sponsor needs to be in valid Catholic
marriage.
It is preferred that a baptismal Godparent will be the Confirmation
sponsor, although ultimately the choice of sponsor is that of the
candidate, who may choose someone who meets the qualifications above.
While it is preferable that sponsors attend the Confirmation liturgy,
it is possible to have a “proxy” stand in for the absentee sponsor (this "proxy" could be a parent).
This has always been the case, but has been more common since the
pandemic.