Sarah, the tutor, ends up playing a significant part throughout the entire story, and Aria actually does end up recognizing her as a true friend (yes, a useful one, but more than that, a friend who stuck by her the entire time drama happened). Aria's just a little slow in realizing that there are people who truly do want to help her out of their own goodness and their liking her. Aria also helps Sarah fulfill her own dreams at the end of the story, so happy endings everywhere.