Having a spouse or close family member as a sponsor may not always be the best approach, especially for younger couples. The main concern is that the ongoing nature of the relationship might make it challenging for the candidate or catechumen to fully open up and embrace their transformation and conversion journey. The sponsor’s role is seen as one of objectivity and companionship, where they should be able to listen to and address the candidate’s doubts and concerns without any bias.

However, in the case of long-term marriages where the spouses know each other very well, having a spouse as a sponsor can be a beautiful and rewarding experience for both parties. Nonetheless, it’s still recommended to carefully consider this decision on a case-by-case basis.

To address the desire of spouses or family members to be involved, you might consider an alternative approach. Those who wish to support their loved ones in the catechumenate process can participate by sponsoring another individual. This approach helps maintain a sense of objectivity and community within the catechumente process.

If you do decide to allow a spouse, fiancé, or family member to serve as a sponsor, the catechumen or candidate should also have a sponsor from the parish.

While it’s not explicitly prohibited for spouses or fiancés to serve as sponsors in the catechumenate process, it is usually not the best option, especially for younger couples. The primary goal is to ensure that the sponsor can fulfill their role as a spiritual friend, be objective, and support the candidate’s journey toward faith without compromising the experience. Ultimately, the decision should be made on a case-by-case basis, taking into account the individual circumstances and the maturity of the relationship.

The basic teaching of the church is that those who are members of the order of the faithful (all the baptized) have an obligation to pray all the prayers that belong to the faithful, that is, the Creed, the Universal Prayer (General Intercessions), and the Eucharistic Prayer. That obligation is given to all the baptized even if they cannot receive Communion. That is why we don’t dismiss children who are preparing for first Communion or those baptized persons who, for whatever reason, do not share in Communion.

There is no directive or option in the Rite of Christian Initiation of Adults ritual text to dismiss baptized candidates or sponsors (who are presumably baptized). So the reference, resource, or rubric you are looking for is one that operates under a principle of absence: the option to dismiss baptized persons with the catechumens is never given.

Now, if the sponsor is the one who is representing the community and facilitating the faith sharing with the catechumens during their gathering after they are dismissed, then yes, they can go out with the catechumens to lead the faith sharing session that follows the dismissal.

However, in that case, that sponsor is serving in the role as a member of the faithful who accompanies the catechumens in their faith sharing. See paragraph 67A. They are not serving in the role of sponsor, per se, at that moment. As a sponsor, their primary role is to show their companion catechumen what it means to be a member of the order of the faithful. And the principle duty of the baptized is to participate in the Mass and offer the prayers that belong to them, the baptized.

Also, see this article for more information: Five things to know about dismissals – TeamRCIA