George's sister

George's sister (Sonia) appears in "Sue Ellen's Little Sister" racing with George in the Brother and Sister Race at the Annual Picnic. The chararcter was never seen at George's house and never seen again. However, she did receive a cameo appearance in "Arthur's Perfect Christmas" where she was dancing with the rest of George's family. Aside from this cameo, the character has yet to make a returning appearance. She is 7 years old.She has also made cameos in several episodes of like in Muffy's new best friend he is seen on a ride with George and in bitzis beau she is seen walking out of school.