The former 'Dawson's Creek' star, who debuted the production by Smash creator Theresa Rebeck on November 5, said that the rehearsal period was far from easy, reported Daily Express.
"I have a hard time sleeping because I think about how serious this all is. I think about the cost of tickets. I think to myself, 'You better do a good job. People are paying a lot of money.' You want to know your stuff," she said.
Holmes made her Broadway debut in 2008 in a revival of Arthur Miller's 'All My Sons'.