Molly MacDonald

Molly MacDonald is a fourth grader and a member of the Tough Customers. Her younger brother is James MacDonald. She enjoys listening to the heavy metal band Mudakrude and in the special Arthur, It's Only Rock 'n' Roll she is the lead guitarist for U-Stink. She also enjoys skateboarding and gives various advice to kids, and her younger preschool-aged brother. In the Arthur Makes Waves she and Arthur become friends, though they have to keep it secret due to their friends' disapproval. Her eyes are always covered by her long hair, unless it is flipped over to the side. Like Francine, she is a tomboy. She also has a Scottish uncle named Miles, which means that the MacDonald's also have a Scottish background.

Personality & description
Molly is a tough tomboy-like character, she can be rude, selfish, and can be a bigger bully than Binky at times. Despite this she still gives great advice, and she helped her younger brother James.

James MacDonald
James and Molly seem to be quite close, James has been shown to turn to his older sister for advice on many occasions.

Arthur Read
Arthur and Molly are shown to be friends in a few episodes, but usually they aren't by the end of the episodes and series.