Earlier quoted context omitted.
It's funny though how different people respond to learning music theory differently. I started on guitar when I was 19. I played for a long time at campfire level. When my kids started learning music I also learnt a lot, and now I know scale shapes and modes on guitar, so I can reasonably play to a song I'm hearing for the first time, then figure it out by ear. But I just cannot make the leap to knowing the notes at…
Your kid might have absolute pitch. Only a few percent of people have it. https://www.youtube.com/watch?v=t3Cb1qwCUvI
I do not have perfect pitch, but I could always do what GP's kid does. I am now a pretty good amateur singer.
What matters for this is learning to read the music notation and developing a sense (mostly subconscious) of scales and harmony. Perfect pitch does not help either of those things.