Caroline is very good. Here are some comments:
She seems a little pre-occupied with trying to play the music and sing simultaneously though.
I recommend that she either really memorize the piano part so she doesn't have to read the music, or even better, sing with an accompanist.
One of the best things about her performance there was that she doesn't fall into the trap of "American Idol" where performers feel the need to emote and belt every note. Her natural sense of nuance and restraint is extremely well served. It adds pathos back to a song that has been butchered by belters for years. Very refreshing, and very effective.
Lastly, (and this is not a big deal) her annunciation is a bit too formal. It seems very stylized. I'm sure she will grow out of this as she becomes more comfortable with the material, and it's certainly preferable to slurring her words, or worse sliding into a note.
I really hope she continues to work on her craft b/c she's obviously got talent.
....but the world goes 'round