2 John 1:13

The children of thine elect sister salute thee.

"The epistle closes with greetings from the members of the church from which John wrote."[26] Many scholars consider that the epistle was actually addressed to a distinguished woman in the church, and that this verse is a greeting from another woman, the sister of the addressee, and her children. Such a thesis is incapable of proof, however; and it makes good sense to view it as a kind of "alert" sent by the apostle to a congregation he was about to visit. This affords an excellent explanation of the personal greetings.

No big point may be made out of this, either way; the big thing in the letter is the instruction regarding "abiding in the doctrine of Christ," not "going onward," and the proper response to known enemies of the faith.