There is a shaykh who told a story of how a young boy came up to him and he was a hafidh of the Quran so the shaykh asked him who was Isa Ibn Maryam and he said “the son of Allah”. Idk if the kid reaches puberty yet or not, do we make takfir based off this?

This question seems to be from someone who suffers deeply from waswas and he is afraid that if he did not make takfir of this unknown person in the story then he becomes a kafir himself. If so, the answer is seek medical attention for your waswas problem and that is what u should be worried about, not this.