She added: "During the finale I had no idea how I would keep going. I had tissues stuffed down my dress just in case I burst into tears."
Les Miserables has been seen by 54 million people in 38 countries. The West End production has lasted longer than the 20-year time span in Hugo's original novel.
The Phantom Of The Opera celebrates its 20th anniversary today. Andrew Lloyd Webber's hit first opened in the West End in October 1986 with Michael Crawford and Sarah Brightman in the lead roles.
It is still going strong at Her Majesty's Theatre. It opened in New York in 1988 and in January this year became the longest-running show in Broadway history.