Woman admits to attack during house party

"My family is way better than yours," 19-year-old Kapurangi Lines said, right before an attack that left her victim with concussion.

After the words were spoken to the victim during a party at their house, another person allegedly jumped in, grabbing the victim's head and pulling them backwards off a stool.

The other person is then said to have put the victim in a headlock, wrapped his arms around them as they were lying face down on the floor, and punched them numerous times.

Police say the victim tried to break free, and the man pulled their arms behind their back.

While this is denied by the first defendant, Lines admits jumping on to the victim's chest and throwing several punches to the victim's head.

The other defendant is said to have held the victim down and punched them a number of times in the kidney area, according to police prosecutor Sergeant Stephen Butler.

The victim suffered a concussion, bruising, ongoing headaches and difficulty focusing.

Both defendants had been drinking at the time, and while the police summary of facts said they had also smoked cannabis, defence lawyer Stephanie Burlace said Lines disputed this.

The police summary also said the victim became unconscious during the attack, but Ms Burlace said this was not mentioned by the victim or two witnesses in their statements.

Ms Burlace said Lines told her she was "abused or threatened" by the victim, and that was why she jumped in.

She has already apologised to the victim through a Facebook message, Ms Burlace said.

She pleaded guilty in the Whanganui District Court on Tuesday to common assault for the offending, which happened in New Plymouth at the victim's home.

In summarising, Judge Dugald Matheson said: "It's a serious incident and I just want to see if I can look at some rehabilitative factors in this."

Lines will appear for sentencing in Wanganui on September 7.

Her co-accused has pleaded not guilty to the assault and is scheduled to appear in the New Plymouth District Court for case review on September 17.