Charlene Amelia Hunt (22), unemployed, and three associates had been drinking when they began shouting racist remarks at an Asian family from Auckland who were walking on George St.
The group followed the family and continued to abuse them and Hunt threw a bottle which missed the 50-year-old victim.
One of her associates punched the man in the face before the group ran away.
Hunt had admitted a charge of a Crimes Act assault and was facing sentence in the Dunedin District Court yesterday.
She was also for sentence on two unrelated indictably laid charges of wilfully attempting to pervert the course of justice, one by using threats to try to dissuade a witness from giving evidence at a court hearing, the second by giving false details as to her identity when police stopped her while driving on August 25.
Crown counsel Richard Smith said prison was clearly the only appropriate penalty, given the circumstances of the offending and the fact the assault was committed while Hunt was on bail on the other charges.
Public defender Andrew Dawson described the attempts to pervert the course of justice as "relatively naive", particularly when Hunt gave her sister's name and details to police.
And in relation to the assault, the defendant had written letters of apology to each of the victims and to the court.
She was genuinely remorseful about her offending and was really "at a crossroads in her life", as she was pregnant and now had another focus to her life, Mr Dawson said.
He asked the court to consider a short term of imprisonment followed by home detention.
But Judge Stephen O'Driscoll said the attempt to dissuade a witness by threats was clearly premeditated and persistent.
Hunt had left a message in a letter box, had made threats through two of the victim's associates and had then used the internet to make threats.
She was granted bail but later committed the offence in August last year when she gave her sister's details, resulting in her sister being arrested and held in custody when she was innocent of any offending.
Hunt was again bailed and was still on bail when she was involved in the race-based assault at Easter.
The influence of alcohol and her peers had been overriding factors in her offending, Judge O'Driscoll told Hunt. And he said attempts to interfere with the course of justice required a "stern" penalty.
On the two charges of attempting to pervert the course of justice, Hunt was sentenced to concurrent prison terms of two and a-half years, with a concurrent six-month jail term for her part in the assault.
