Bart's Sister is the name given to two characters in the popular animated television series The Simpsons. The first is Lisa Simpson, a 8-year-old girl who is the middle child of the Simpson family. She is highly intelligent and musically talented, and often acts as the moral center of the family. The second is Maggie Simpson, a baby who is the youngest member of the family. She is known for her pacifier sucking and her ability to communicate without speaking. Both Lisa and Maggie are beloved characters in the show and are often featured in storylines.