You may want to read the following by Raija Sollamo: Repetition of the Possessive Pronouns in the Septuagint
Essentially, Raija showed that in normal idiomatic Greek writing, the possessive pronoun would either be omitted (as the relation between the subject/object and the possessor was deduced based on context), or would only appear once in the clause. It's position in the clause could be anywhere, though most commonly before the subject.
In translational Greek however, especially that of the Septuagint, the writers would nearly always follow the Hebrew/Semitic authors repetition of the possessive pronoun, with very few cases where idiomatic Greek would prevail. The Psalms especially are an example of slavish Greek translation, rarely omitting a repetitive possessive pronoun.
Though mainly applying it to lists of coordinating items (my eyes and my feet etc., etc.), I would expect it to apply in other cases as well.
As such, I believe the textual variants you have above are examples in the NT where scribes have sought to 'smooth' the translational Greek syntax into a more idiomatic Greek one, in this case the omission of the second possessive pronoun in a clause.
This should come into play when textual variants are being decided, IMHO. A Greek scribe would not likely insert an extra possessive pronoun, but rather omit it.
What does THGNT have at John 2:12? There we have a textual variant that either has two, or three uses of the possessive pronoun αὐτοῦ:
Μετὰ τοῦτο κατέβη εἰς Καφαρναοὺμ αὐτὸς καὶ ἡ μήτηρ αὐτοῦ καὶ οἱ ἀδελφοὶ [αὐτοῦ]* καὶ οἱ μαθηταὶ αὐτοῦ, καὶ ἐκεῖ ἔμειναν οὐ πολλὰς ἡμέρας.
incl: P66c A (❦ K, Ws) Θ f 1.13 33 m lat sy
omit: P66*.75 B Ψ 0162. (579) pc c
Interestingly, P66 has the insertion
of the third possessive pronoun. Good evidence that a 2nd exemplar was being used?
Idiomatic Greek would either have none or just the one. One of the few places in GoJ where a Hebraism made it through