Perhaps the best path is to inquire of the nun discretely and charitably for some explanation. It is unclear to me also whether the situation represented the Rite of Sending or the Rite of Election.
Though I would agree with Brother Rich, that there is no room for viewing these rites as mere formalities whose manner of celebration is subject to whim and no reason to introduce errors into their celebration. While I do not know all the circumstances or any particular law on the catechumenate in your episcopal conference or diocese, some general comments can be made.
- Sending is different from Election, of course. The Rite of Sending is optional (Rite of Christian Initiation of Adults, no 106) but a diocesan bishop could mandate it, I think. Moreover, the Rite of Sending would normally be conducted by the parish priest.
Signing the Book of the Elect at the Rite of Sending is omitted if it is to be done in the presence of the bishop later (RCIA, no 113).
If done at the Sending, “the catechumens may come forward to sign it or they should sign it after the celebration or at another time prior to the Rite of Election.” (ibid.) We’ll revisit that.
- However for informational purposes, the following should be noted about Election from the RCIA, no 121:
2A. “Admission to election therefore belongs to the bishop, and the presiding celebrant for the rite of election is the bishop himself or a priest or a deacon who acts as the bishop’s delegate (see 12).” With such delegation, therefore, a priest or deacon may lawfully celebrate the Rite of Election. Further, it may be celebrated in a parish (RCIA, no 106).
2B. The actual inscription of the names at Election may be carried out in various ways. Again the RCIA, no 133 mentions: 1) self signing, 2) signing by the godparents, or 3) even signing by the minister presenting the candidates.
At Election, the “RCIA” team leader could fall into the third situation. As long as an individual manifested the will to be received or enrolled as the Elect to her, it seems to me that she could sign it herself or delegate others to sign the book on her behalf. This reflects an ancient principle of law, that one may do through others what one can do personally. (Potest quis per alium quod potest facere per seipsum.)
- While it is not clear that the situation is one of Signing or Election, what could be done at Election could also be done at Signing, since the greater contains the lesser. (Plus semper in se continet quod est minus.) There may be provisions in the norms of your episcopal conference or diocese to consider here, too. These are subtleties of law perhaps. It certainly makes more sense in principle to me for people to sign their own names when it can easily be done. There is a profound sign value here for the individuals, the community, and their teachers.
- Two broader questions strike me as serious ones. What should be done when adults seeking initiation cannot be present at the Rite of Election since it does call on them to manifest the desire to seek baptism, to prepare properly for it, and to be recommended? Or even at the Rite of Sending, although it is optional, which also speaks of disposition, and make a preliminary assessment of readiness?
These points could be discussed with the team leader apart from the concrete circumstances which are presented, so that you may approach your service with a peaceful mind again. But again, it’s not clear to me which Rite is presented in the original post.