Where is the Pronoun Antecedent?

Look at this sentence:

Sr. Leni is Gabo's Religion teacher, and the conference was part of the preparation for his first communion.

Notice the 'his' in bold font. We call that a pronoun, and a pronoun replaces a noun. So we look back in the sentence and look for that noun that the pronoun 'his' replaces. Can you find it?

We sure can find many nouns before the 'his.' There are six nouns before 'his' - Sr. Leni, Religion, teacher, conference, part, preparation. Can 'his' replace any of these nouns? I don't think so.

The only noun that 'his' can replace in that sentence would have been 'Gabo.' But the form of 'Gabo' is not a noun, it's in the possessive, Gabo's, so that doesn't count.

In other words, the pronoun 'his' has no antecedent in this sentence. The sentence should be:

Sr. Leni is Gabo's Religion teacher, and the conference was part of the preparation for Gabo's first communion.