Maddie Santoriello was born in New York, NY in 2006, and resides in New Jersey. Most recently, she can be seen on HBO's The Undoing as Sylvia (Lily Rabe)'s daughter. Maddie's voice can be heard on Elmo's Wonderful World in Seasons 47 through 50 of Sesame Street, as well as MLB's Play Ball Little League campaign, and a radio commercial for Nellie's Eggs. Maddie has also appeared on the Today Show, National Geographic's Brain Games, and Good Morning America. Maddie plays several instruments including piano, drums, banjo, marimba, vibraphone and ukulele.