[Cvengr]

Even more importantly, the Greek doesn’t say “you’all’s” mother, rather the object of the mother is directed to one person, the disciple. Nice thing about the Greek is that it so explicitly declares the nature of the object and subject.

[annalex]

Yes, the adoption is literally described between the individual disciple and Mary, but the next sentence uses plural: the disciple took Mary "eis ta idia". This shows that the disciple understood the adoption to extend to all disciples who are "of his own".

John
	English: Douay-Rheims	Greek NT: Byzantine/Majority Text (2000)
	John 19
26.	When Jesus therefore had seen his mother and the disciple standing whom he loved, he saith to his mother: Woman, behold thy son.	ιησους ουν ιδων την μητερα και τον μαθητην παρεστωτα ον ηγαπα λεγει τη μητρι αυτου γυναι ιδου ο υιος σου
27.	After that, he saith to the disciple: Behold thy mother. And from that hour, the disciple took her to his own.	ειτα λεγει τω μαθητη ιδου η μητηρ σου και απ εκεινης της ωρας ελαβεν ο μαθητης αυτην εις τα ιδια

It is unfortunate how often Protestant translations obfuscate that passage.