Oh, Smurfette is actually interesting. Smurfs are a single-gender species in nature, but Smurfette was created by an evil wizard to inflitrate the smurfs and help the wizard capture them. So the fact that her only personality trait is “girl” is actually diagetically justified and it can lead into some interesting directions. That said, after breaking free from her programming she has the personality traits of guilt for her past actions and appreciating a new family. So there’s actually a bare minimum of depth there and tons of room to grow the story and the character in interesting directions, though unfortunately that promise wasn’t really explored because… it’s the fucking smurfs