Lucy

Lucy is the maternal aunt of Arthur, D.W., and Kate.

Past Life
Lucy grew up near an unidentified town on Grandpa Dave's farm (inferred as her dad (Grandpa Dave) is said to have lived there for a long time).

Later life
Lucy's family attended her wedding.

During a timeout in her room, D.W. exaggerated past events and made them sound worse than they really were; like not being able to attend Lucy's wedding, and being forced to stay home and work as a slave, instead.

Appearances

 * 125a. "D.W. Thinks Big"
 * 204b. "Go to Your Room, D.W." (mentioned)
 * 207b. "Night Fright" (mentioned)
 * 703a. "Ants in Arthur's Pants" (mentioned)
 * 1510a. "Grandpa Dave's Memory Album" (photograph)

Trivia

 * In every later episode that mentions her, she is referred to as a cousin, instead of their aunt.
 * Sonja Ball, who was the voice of Lucy, is also the voice of her sister, Jane, in the series.