You would imagine somewhere around 10-12yo he "saw for himself" things online. Maybe his parents' immediate friend group do not mention her career, but inevitably she is recognized in public, or has stuff lying around the house from conferences and promo material and such.
Is home school mandatory? Religious school probably wouldn't take the kid, as other moms would freak. Maybe a very exclusive private school? Mom's probably worth 6M.
whatever scientists call the incest repulsion still exists, and this kid must constantly have to confront his mother's lechery. Even if people arent judgy, he's in a very tough place