Hyatt died on June 2, 2010 after being involved in a fight outside a house party that had spilled out into the driveway after being broken up by adults.
The accused took the stand on Tuesday, but cannot be identified because she was a minor at the time.
The young woman told the jury that Hyatt and some other girls had been harassing her for supposedly kissing a boy at the party who was not her boyfriend.
She said she was trying to find her boyfriend to straighten things out when she says Hyatt and the host of the party intervened.
Teens fight, Hyatt stabbed in scuffle
She testified she pushed at the two girls, and they pushed back — starting a brawl between the three. She said the next thing she knew she saw Hyatt on the ground, and a knife in the other girl's hand.
The accused said she struggled to get the knife from the host's hand and then admitted to swinging it around to keep the girl back.
She testified when others broke up the fight, teens began yelling that she had stabbed Hyatt, and she took off for a friend's house.
Under cross-examination, the Crown prosecutor brought tears to the defendant's eyes as lawyer Murray Kaay grilled her about what she told that friend after leaving the scene.
She insisted she didn't stab Hyatt, and though she had six to eight shots of whiskey testified she was always in control of her actions.
Through the course of the three-week trial, none of the witnesses testified to actually witnessing the accused stab Hyatt, but the teen was seen holding the knife during the scuffle and after Hyatt was stabbed.