IT was bad enough when Colleen Gudmann learned police had found her drunken 16-year-old daughter trying to use fake ID to get into a pub.

IT was bad enough when Colleen Gudmann learned police had found her drunken 16-year-old daughter trying to use fake ID to get into a pub.

But when the hairdresser went to the station to collect her, things quickly got worse.

By night's end, it was Ms Gudmann who was locked up on an assault charge and facing a police AVO - all for exercising what she says was normal parental discipline.

Police arrested her after she argued with her daughter Victoria, who lashed out at her mother, calling her a bitch.

Ms Gudmann says she did what most parents would in her situation: she gave Victoria a small slap on the cheek to pull her into line.

"The next thing I know, the policewoman yelled at me to 'Get out, go!' They took me to a room and said they were charging me with assault and were taking out an AVO against me," a still-shocked Ms Gudmann, who lives in Northbridge, Sydney, said.

"I said, 'Are you joking?' I couldn't believe it, but they said it was on CCTV and they had to charge me.

"I had to empty my handbag, they fingerprinted me, put me under these big spotlights and took my photo. It was absolutely horrible.

"I had to sit there until 5am waiting for the AVO to come through, so even though we live together, Victoria wasn't allowed to be released into my custody.

"The whole thing just got blown completely out of proportion. I still can't believe it happened."

The November 6 drama was the first time Ms Gudmann had set foot in a police station.

Two weeks later, she experienced another first, fronting Hornsby Local Court as a defendant - on Domestic Violence Day - while Victoria, a Year 11 student at Killarney Heights High School, was questioned by social workers about whether she feared for her safety.

Magistrate Lesley Brennan dismissed the case under Section 10 of the Crimes Act, recording no conviction.

"The magistrate said, 'This is just a parent exercising their right to be a parent - this is absolutely ludicrous', " Ms Gudmann said. "When we walked out of the court, Victoria just broke down and cried.

"She understood the severity of the situation. She was grounded for the month, but it was the stress of my life.

"I'm not a bad person, but I can think of only three times in her whole life when I've hit Victoria if she was naughty."

Victoria added: "It was nothing - it was really nothing at all. I was like, 'What's the big deal?'

"I mean, aren't there more important things to do? Aren't there people dying?

"I just wanted to go home with my mum - I wanted to see her. We were all so stressed out. It really sucked."

Under NSW law, parents and guardians have the right to discipline children, provided the punishment is reasonable.

Chatswood police duty officer Stefan Kent said striking a child's face was assault.

"She assaulted her in the charge room, in front of police," he said.

"That's no different from it occurring in their home or in the street or anywhere, for that matter."