Maddie Baillio has been cast as Tracy Turnblad in the live TV production of Hairspray!

The young star has known for almost two weeks that she nabbed the role but she had to keep tight-lipped. Oddly enough, Baillio decided to audition only three hours in advance.

“I decided at, like, 3 a.m. the night before that I was going to get up and go to this audition,” Baillio tells PEOPLE.

Rehearsals for the show start in October. Baillio joins a star-studded cast, which includes Harvey Fierstein as Edna Turnblad, Martin Short as Wilbur Turnblad, Jennifer Hudson as Motormouth Maybelle and Derek Hough TV host Corny Collins.

Hairspray Live! airs Dec. 7 on NBC.