She was now a celebrity - which put her in a clique of one.
Still, O'Neil skipped out on the banquet part of the evening.
Plus, when O'Neil came back to school, she was nervous and hid in the music room, working on the distance courses rather than joining classes that had started eight months earlier.
And she focused on school work rather than sports, socializing or theatre.
"As an adult, when I would phone her and it took her several weeks to get back to me, I realized it was because her time is not her own.
There are all of these crazy demands and new things happening and it's really easy not to call someone back.
"It was such a good, exciting environment through the whole Idol voting thing," says former classmate Dan Hasegawa, 18 (who played Tony to O'Neil's Maria).