Craig's little sister is a precocious little girl. She has two things in common with the rest of her family - she's an animal lover, with a soft spot for cats, and she happens to flip people off, sometimes without realizing it.
- Though she has never been given a name in-series, most fans refer to her as Ruby.
- Her character model has been re-used many times, including as a background fourth grader in many episodes at school, and as a daughter from a different family in "Major Boobage".
- She also has yet to speak in any episode.