Although im a big fan of Nancy, she was not using her real voice to sing the songs in KMK, I was surprised to hear her soprano voice in Fanny Hill. You've said this about three times and you're wrong. How is it not her real voice? Is she lip-synching? NO.
If she chose to alter her voice to suit the character then she modified the sound of her real voice in order to achieve her own interpretation of Lois Lane/Bianca.
Is JLY not using his "real" voice in JERSEY BOYS because he sings in falsetto? No. He has a character to play and that's how that character is supposed to sound. Would Angela Lansbury not be considered using her real voice in the revival of GYPSY because she didn't use her accent? No.
So, no matter how you slice it, Nancy Anderson
IS using her real voice. She's just chosen to use a certain register. Which, to me, makes her a fine actress that she can achieve such versatility. If she doesn't use her soprano, it doesn't mean she's not using her real voice. You can't fault someone for not using something when it's not needed.
"I love talking about nothing. It is the only thing I know anything about." - Oscar Wilde