A teenage girl will spend another month in jail for beating an elderly woman with a metal table leg last summer.

The 15-year-old girl was sentenced Friday to an additional 30 days in jail and 15 months' probation for her part in a violent assault in the Halifax Common.

She has been at the Waterville youth detention centre since her arrest in August.

"You will never be able to take back what you did to that woman," Judge Patrick Curran told the girl, who can't be named under the Youth Criminal Justice Act.

The teen was one of three girls charged with aggravated assault.

One night in August, a 66-year-old woman was walking through the Common when three teens swarmed and hit her with metal table legs they pulled out of the trash.

The attack only ended when a passerby with a dog scared the trio away.

Teen a model prisoner

Outside the courtroom, the husband of the victim told reporters he was unhappy with the sentence and would not comment.

"I am really sorry for her [the victim] and for everything that happened," the girl's mother said.

Curran conceded the case posed a dilemma for him.

Though he condemned the attack, he also noted that a report from the teen's jailers said she was among the best-behaved prisoners in Waterville.

The prosecutor wanted the girl to spend an additional year in jail. But Curran said the teen's decision to plead guilty was a key factor in sentencing her to only 30 more days plus the probation period.

Curran also ordered her to stay away from the other girls involved in the attack.

The two other teens have pleaded guilty and will be sentenced later this month.