She left school at the age of 19, when she was cast in the 1993 Los Angeles production of Andrew Lloyd Webber's Sunset Boulevard,[2][5] After a nine-month run, she moved to New York for the musical's 1994 Broadway opening.

She has been seen on Broadway in Les Misérables, Sunset Boulevard with Glenn Close, Side Show, and Cinderella with the New York City Opera.

She originated the role of Cathy in Jason Robert Brown's The Last Five Years in its Chicago premiere, but opted to do South Pacific at the National Theatre in London instead of following the show Off-Broadway (she was replaced by Sherie Rene Scott).

In 2004, she starred as Emma Carew in the concert-style version of Jekyll & Hyde – The Musical entitled Resurrection, opposite Kate Shindle and Rob Evan.

[citation needed] In 2005, Kennedy starred in the world premiere of Frank Wildhorn & Jack Murphy's Waiting for the Moon, as Zelda Fitzgerald, which took place in Marlton, NJ.