Our DD8 is silly and outgoing, but there are still so many ways in which she shows off her intellect just by being herself. For instance, we recently had an adult visitor in our house, and with her parents occupied, DD decided to occupy herself by using her white board to validate that "Tom Marvolo Riddle" really was an anagram of "I am Lord Voldemort." The visitor couldn't help but notice, and comment (positively).