It was all over the news when it was announced that Sutton was getting the role: Kerry turned it down in favor of a previously scheduled project (what project, I have no idea). It seems a little odd to me, because Kerry was with Little Women from the very first workshop, but I heard that after the last reading a lot of the creative team was replaced, so maybe she wasn't happy with the new changes and decided not to do it.
In the meanwhile, she's playing Sharon in Finian's Rainbow at the Irish Repertory in NYC for another couple of weeks.
Kerry's website
"Peace! The charm's wound up."
--Macbeth