Last week a jury found Renee Joy Payne, 26, guilty of assaulting the woman in October 2012.

She was found not guilty of wounding.

The assault occurred at the victim's Prospect home following a heated argument between the two women.

Yesterday in Launceston's Supreme Court Justice Robert Pearce delivered sentence.

Justice Pearce rejected Payne's evidence that the victim had threatened to "f--- her up" or had shadow boxed in front of her face.

He said Payne had not told police this in an interview shortly after the incident.

Instead he found Payne had struck out at the woman in anger but that the attack was spontaneous and not premeditated.

He rejected her evidence that she was not conscious that a bottle of beer was in her hand at the time.

Justice Pearce said the victim was left with a permanent scar requiring cosmetic treatment.

He found there was little chance of Payne reoffending.

She was sentenced to two months' jail wholly suspended for 18 months.