If Barnette can figure out how to convince one or two of the candidates in lower positions in the polls to drop out and endorse her before the debate, and she can make a memorable positive appearance at the debate, she stands a good chance at getting the nomination. If all the other candidates stay in the race, they’re just fighting for fourth place.
She could be improving due to McCormick and Oz attacking each other - she is not personally taking any of that damage they are inflicting on each other.