Lacey Nicole Chabert (born September 30, 1982) is an American actor. Well-known for on-screen roles in Mean Girls and Party of Five, she is also an accomplished voice actress; among her more prominent voice roles are Eliza Thornberry on The Wild Thornberrys, Gwen Stacy on Spectacular Spider-Man, Zatanna on Young Justice, and Meg Griffin on the first season of Family Guy.
Also, she was in that Lost in Space movie and the notoriously awful 2006 Sonic the Hedgehog game, but try not to hold that against her.