After more drinking, Byrne and the victim became involved in an argument about 1am. The victim lunged at her, grabbed her and pinned her on the kitchen floor. Byrne responded by biting the victim's knee.
When the victim put her hand over Byrne's face and began pushing it away to stop the biting, her little finger went into Byrne's mouth. Byrne latched on with her teeth and bit down with so much force the top half of the finger was bitten off.
Byrne got up and spat the piece of finger on the floor before leaving the house.
The victim was rushed to hospital and underwent surgery to re-attach the top half of the finger.
The surgery was unsuccessful and the victim lost the top half of the finger.
Byrne told police she could remember biting the finger "but not much more".