With all the talk on the "Hello Megan" catchphrase, I just wanted to kick in my thoughts on Miss Martian.
From Bereft we got an input of M'gann's thoughts as they were before coming to Earth and we learned that, internally, she isn't as totally alien as one might reasonably expect a Martian to be -- so at least shortly before coming to Earth, she was functioning reasonably like a human being in her internal mental states (people rarely write aliens as alien because its hard to connect to an audience of humans).
BUT we do have that marvelous moment in Schooled where she loses track of her humanoid configuration and starts popping arms out of the side of her head etc.. IMMEDIATELY after that moment, she encounters Wally who reacts to her bizarre form with a paniced revulsion and, quite tellingly, SHE mimics his reaction -- a mirror effect-- as though she doesn't understand what he is doing or why but is trying to relate to him by simply emulating the emotional response she doesn't understand-- its clearly her most alien moment so far in the series and gives a real glimpse of the fact that this isn't a real human being (which, of course, she isn't) but somebody who has MADE herself become a "human being".
Now we know at this point, that no matter how close M'gann is in her mental states to human, she has constructed the human persona "Megan" by watching an old sitcom called "Hello Megan" and completely adapting the character of the lead to get her human appearance and attitudes. You should compare the scenes in the movie "Justice League New Frontier" where J'onn finds himself on Earth and creates a human personna for himself by watching television shows and becomming various characters from the movies, shows and ads. I think the writers are clearly indicating that M'gann did something similar (or even identical) on Mars as a part of her desire to become an Earth citizen (for whatever reasons, perhaps, ironically, alienation from her Martian family)
So EVERY personality trait Megan is showing is her interpretation of a character -- that of the character "Megan" of "Hello Megan". So her use of the catchphrase, her making cookies and her general response (even deference) to "the boys" (you'll notice she has absolutely no problem emulating Red Tornado even though his is a generally masculine figure) is a part of her interpretation of that character as her baseline for how a human should react and behave.
All of which just might have some very disturbing implications for the romantic relationship between her and Superboy -- talk about a messed-up situation, he's a 6-month-old child pumped full of adult knowledge and she's a telepathic alien trying to act human... very, very, weird (but, HEY, Comics!)