Spelling of her name aside, I think the OP is asking a legitimate question-and it's one I'd also like to know the answer to. When the Broadway production was first announced with Roger still playing the title role, I remember there being backlash from posters complaining about her vocals on the cast recording, saying that she really couldn't sing the role. Then there were another group of posters saying that they saw her in London and, although they acknowledged she didn't have the vocal power to sing the score like Patti or Elaine, Roger was giving an electric performance that was not to be missed. Now she gets to Broadway (yes, same show, same role, same director, etc), and very little of that buzz is still around. So maybe her performance really was better in London than Broadway. Seems very odd to me, but possible.
"Art, in itself, is an attempt to bring order out of chaos."-Stephen Sondheim