If I were advising her, I'd ask her to reprise her 3rd solo audition --- Independence Day ( this time with country background music, instead of the a capella she did ).
Only, my advise is for her not to start from the beginning of the song but from the chorus that starts with the crescendo that starts with the words -- LET FREEDOM RING !
You only have a few minutes in a group of 12 to highlight your vocal abilities and starting the song from the slow beginning won't impress.
Start from the middle, return to the beginning and repeat the crescendo. That'll do it.