On the voice she has said some very ESFP and very ENFP things:
ESFP) On one occasion she was analyzing a girl's performance and then randomly remarked on a tattoo on her leg but make no abstract conclusion based on that.
She's very very VERY into fashion.
ENFP) She is all over the place.
She said to one contestant last night "everything you are is so sparkly right now"
So my conclusion is ExFP.
You know what, she kind of reminds me of a less egotistical and abrasive version of Adam when she is on the voice. I suspect that he is ExTP leaning ENTP (the ADHD is very apparent in him).