Emma was in the Broadway revival that was here a few years ago starring Gary Beach and Daniel Davis. It played for a few months through the beginning of 2006. There was a bit of a scandal when Davis was fired quite suddenly and it didn't last much longer past that. It was directed by her Dad though so I think we all know how she got that part.
The production was choreographed by Jerry Mitchell so it appears that they knew each other before the "Legally Blonde" audition. Besides subbing for the lead in "Tarzan," Celina was also the Miranda in the opening sequence of the "Sex and the City" movie where Carrie sees four girls resembling a younger version of the foursome. Kate Rockwell from the "Grease" reality show was the Samantha in that scene.
It doesn't surprise me that the house was a deal breaker for a lot of people. That element was just added for drama and cattiness and does nothing but show which girls have bad attitudes.