Foremost, both the Greek and the Latin are intentionally and appropriately vague in the language used in John 19:27. Opposed to most English translations which reference โinto his care, house, or homeโ, both the Latin and the Greek translate to โto his ownโ.
A more appropriate translation for the verse would be:
โAfter that, he saith to the disciple: Behold thy mother. And from that hour, the disciple took her to his own.โ
Even Luther interpreted (the same as the Catholic and Orthodox) that in the beloved disciple are prefigured all the disciples of Christ. By his gift from the cross, Christ makes Mary the spiritual mother to us all.
Although Luther references Mary as mother to all multiple times, Christmas of 1529 is one of the clearest, โMary is the mother of Jesus and the mother of us all. If Christ is ours, we must be where He is, and where He is, we must be also, and all that He has must be ours, and His mother therefore also is ours.โ
Said by people that say "behold thy mother" without reading the rest of the verse