When DD was 3, she was very aware that others could not do all of the things that she could do. But try as I might, I could not convince her that she could not simply explain/teach others to do everything she could. I remember in particular one conversation we had about what she would do with a T. Rex if one were alive today. I tried to explain that a T. Rex had such a small brain that it would not be able to even learn to understand English, much less play board games with DD. Heaven only knows why I tried, but I did. She was adamant that she would be able to teach it to speak and read and play games (and not eat her). She could not be convinced otherwise. Around that same time, I overheard her trying to teach her friend's new baby sister to read & talk & whatnot. LOL.
So I say good luck, Amanda.
Oh, and I should also say that now that she's 4, she does understand it. It's not a giftedness thing, but just a people-are-different-and-have-different-interests-and-issues-and-abilities thing. I think it helps that DH is dyslexic and an awful speller.