Judith Anastasia "Judy" Funnie is the older sister of Doug Funnie. She's often seen with a flair for the (overly) dramatic, usually seen wearing only purple and black, and rarely takes off her beret nor her sunglasses.
At 16 years old, Judy is the oldest child in her family and while she's never particularly rebellious, she's very dramatic (due to being an actress) and often difficult to deal with.
However, she's very intelligent and artistic and therefore attends the Moody School, a school for artistically talented teenagers. Judy is sometimes tapped to give or direct performances at Bluffington Elementary, and although Doug initially dreads these events out of fear that Judy will embarrass him (as she has done in the past), Judy's productions usually turn out to be well received.
She has red hair. She wears a purple sweater dress, a black shirt, black tights, and purple boots.
Doug is her younger brother. Although she and Doug have sibling rivalry like any normal pair of siblings, she loves him and it's very clear that they're close, and her teasing of him is usually good-natured.
As with her younger brother, Judy is caring of her younger sister.
Judy is caring of her mother, though questions her authority sometimes. An example is seen in the movie where she questions Theda telling her off for the "mess" she made (it was Doug and Skeeter bringing Herman Melville in the house)
Roger is Judy's secret crush, from his side, anyway. Maybe?
In the Disney version of the show, the Sleech bros seem to take an interest to her.