Sue Ellen's Little Sister is the second part of twentieth episode and last episode of Arthur Season 2. Sue Ellen's Little Sister aired on May 25, 1998. It aired with the episode "How the Cookie Crumbles".
Sue Ellen feels left out about not having a sibling, so she opts for one of her friends, but they each have their flaws. She learns about the dangers of having a younger sibling and later, she gets a letter from a boy named "Tenzin" living in Tibet who is her pen pal or de facto brother.