Tineka Sinclair doesn't remember what she was thinking about as she wandered home from school that warm summer's day, trailing behind her brother Mark, aged 14. A quiet eight year old, she was probably wondering if she'd be allowed to play with her friends that evening, she says, or guessing what her mum, Gloria, had made for dinner that night. But no matter what was running through her mind, she could never have pictured the hellish sight that greeted her as the family's three-bedroom, fibro home in Sydney's Western suburbs came into view.

On the front lawn, a group of neighbours had gathered, and were staring in hushed horror at a ground-floor window. Tineka's father, Bruce, a muscle-bound council worker, was holding Gloria halfway out, gripping her tightly with one hand. In the other, he held a rifle, pressed firmly against his wife's temple. Even from where she stood, Tineka could see the blind terror on her mum's face. It was an expression she had seen too many times before.

The little girl started to run, screaming, towards her mother, but neighbours held her and Mark back before they could get anywhere near. "I just felt helpless," Tineka says now, wiping tears away from her eyes. "We just couldn't do anything to protect her."

A child shouldn't have to worry about protecting her mother from abuse; and no child should ever have to experience the sheer terror that Tineka felt that afternoon in 1980. Yet, her experience is tragically common. Today, a staggering one in four Australians aged 12 to 20 witness domestic violence, a figure highlighted in a report by the White Ribbon Foundation released last November. That's half a million children and teenagers who know their mother or step-mother is being abused by her partner. In September, Prime Minister Kevin Rudd described family violence as "the great silent crime of our age".

Until now, government programmes against domestic violence have mainly concentrated on helping and supporting its female victims. There are many; in fact, one in three women will experience domestic abuse at some point in their lives. But, says Dr Joe Tucci, of the Australian Childhood Foundation, there's a growing realisation that children like Tineka, the silent witnesses of this violence, need help, too.

"It's only in recent times that we've started to appreciate the impact violence has on children," he states. "The focus has been, I believe, on women as the targets... and I think kids have been an afterthought."

Yet the effect on kids of watching violence can be profound - in fact, it's as damaging for children as physically experiencing the violence themselves. "It can be just as traumatic for a child to see their father being physically or sexually abusive to their mother, as it is to be assaulted [themselves] by their father," believes Dr Michael Flood, co-author of the White Ribbon report. "It's deeply traumatic for children."

Even seeing the aftermath of violence - their mum nursing a bleeding nose, or bruises - can cause anxiety and behavioural problems, adds Tucci. Many of these children are constantly on edge, trying to stay alert to danger, and this reduces their ability to concentrate at school, or even make friends. "They feel anxious about leaving mum to go to school in the morning, in case they come back and she's not there - or worse."

The problem is, for children living with domestic violence, these fears are sometimes justified, as Tineka knows only too well.

To read more about Tineka's story and how domestic violence can affects children witnessing it, read this month's marie claire