Carly Spencer was Sam's second love intrest. We don't have much to say about her - you can see what she looks like here. All you really need to know is she's in the movie to replace Megan Fox, look pretty, scream for help, never get her clothes dirty in the midst of a giant Transformer War, her character serves no point in the story, and at the end she gets killed when the villainous transformer eats her. We're sure you can find more information on this pointless character elsewhere.