I actually saw it with my 12 year old cousin.
Personally, for her, it was more just to see kristin chenoweth and sean hayes rather than what the play was actually about. I don't know how much of the play she actually paid attention to. She was just more interested in the music.
If we lived on the east coast we would definitley take her again so obviously we dont see anything wrong with it but it is of ocurse a personal choice.
Unfortunately, I dont remember enough of the specifics of the play (I was mainly there to see Kristin and Sean as well...lol) to really give you an idea of if you think it would be appropriate but I just wanted to let you know that I had taken a 12 year old to it and no ill effects...haha
Kristin is actually staying until the show closes on Jan.2nd She decided that since she and Sean started together, that she wanted them to finish together. She is missing the 28th-1st though i think because she is performing in Los Angeles New Years Eve.