Lucy

Lucy is Arthur, D.W., Kate, and Cora's aunt who was married in "D.W. Thinks Big." She is the sister of Jane and Fred; and the daughter of Grandpa Dave. Although not appearing again, she is mentioned several times, such as in "Night Fright" and "Ants in Arthur's Pants." A picture from her wedding appeared in "Grandpa Dave's Memory Album." She is also mentioned in "Go To Your Room D.W." in a dream (which the staying home part never happened as said by her imaginary friend Nadine).

Past Life
Lucy grew up near Unidentified Town on Grandpa Dave's Farm (inferred as her dad, Grandpa Dave, is said to have lived there for a long time).

Trivia

 * In every later episode mention, she is referred to as a cousin, instead of their aunt.
 * She is voiced by Sonja Ball, who also voiced her sister Jane in the Arthur series.