Charlotte "Charlie" Duncan (Mia Talerico) is the title character and the second youngest of the Duncan children. She is generally portrayed as being happy and rarely cries. Charlie appears as the least of the Duncans in the series as she is little. It sometimes takes a few tries to get her to do the right thing. Charlie can also be mischievous at times. Many of the Duncan family's adventures revolve around Charlie. Both her older brothers, PJ and Gabe, are often seen using Charlie for their own benefit, although PJ shows that he cares about her deeply. However, Gabe seems to dislike Charlie the most although, in some episodes, he is seen being quite fond of her. Amy thinks of Charlie as the perfect baby, being cute and all that. Bridgit Mendler played an older version of Charlie in Bye-Bye Video Diary, in a dream sequence that shows what Teddy fears if Charlie does not receive the video diaries, Charlie might act badly, quit school, run away with her juvenile boyfriend, and resent Teddy. It was revealed in Charlie is 1, that it was Teddy's idea to nickname her Charlie. Charlie was seen having short hair, usually tied up like a bun in the first season, but as she grew older, had longer hair in a ponytail or pigtails. Charlie speaks more often in later episodes of Season 2 and in Season 3. She shares a birthday with Toby and said, "I like this present" when Toby was born. In Season 3, her personality begins to develop, as she is seen as sneaky and mischievous, such as pretending to like a doll Amy bought for her to like Toby, but then throwing it away when she wasn't looking, and also telling Amy's "friends" what she really thinks of them, causing her to lose them all. Her personality is most like Gabe.