I loooooove the video "The Heat Is On.. The Making Of Miss Saigon"! It has wonderful film footage of Lea's audition (as posted above), also of the show itself. Alan Boubil and Claude Michael-Schonberg(sp?) along with Cameron Macintosh all look stunned as she sings for them at the piano for the first time. It's an amazing moment. They're all unable to speak for a moment, then they just say, "Ok, Go in the middle and sing it... NOW!". She also asks them to sign a Les Mis poster or something of that nature and I think it's funny to see how she ended up being the "Dream Version's" Eponine!
Also, you can see some of Ruthie Henshall rehearsing in the ensemble numbers. I believe later in the film, they show her running to a quick change backstage and she mutters "This show is a Blockbuster and I'm in it!!"; obviously excited at how opening night was going.
Miss Saigon is a great show. I'll always love it.
"All I want is the truth, just give me some truth!"- J. Lennon