Yes she did, in the episode that introduced me to the series (wow, it's already nostalagia to me...) I guess that could count, but I mean if you had make a quick sentance like "You can't go on your own, you're just children." how would it be said? Saying a paraphrase of the shows title (totally the reason they made Twilight say it) would sound odd. Thanks for answering though - I want to get the dialogue right for a project I am working on.
In other news, I saw Sleepless in Ponyville tonight, and I loved it! Highlights were; Scootaloo finally getting and episode, Rainbow Dash behaving the way I expect her to, after all the development she had last season, previous gens being refferenced again (keep it up, writers!), and something that I've been waiting to happen finally happening!