Canberra Labor MP Gai Brodtmann spoke of Ms Costigan's brutal killing in federal parliament on Thursday, after receiving an email from a family who knew the children.

The family begged Ms Brodtmann to take action to prevent another woman being killed.

"We cannot stop thinking about what Tara's two boys saw last Saturday," the email read.

"They will never, ever get over it.

"They will have that memory etched in their brains forever, flashing back to that moment for the rest of their lives."

Ms Brodtmann said the killing had sent shockwaves through the Canberra community, but she was proud of the way the city had responded.

More than $75,000 has now been raised to support Ms Costigan's three children, two boys aged nine and 11, and a newborn baby girl.

A walk around Lake Burley Griffin later this month to make a statement against domestic violence is also gathering momentum.

But as the donations flow for Ms Costigan's children, local support services continue to struggle to meet the need.

The Domestic Violence Crisis Service, which plays a critical role in helping vulnerable women, said a lack of funding, coupled with increasing demand for support, has left it stretched, and able to only deal with cases at the "pointy end".

Local refuges are struggling to find beds for women in need, while federal funding cuts mean the Women's Legal Centre ACT will have to turn away 500 clients in two years.

The majority of those women are victims of domestic violence and are on low incomes. The cuts mean many of those women are likely to be left stranded in the court system.

ACT Attorney-General Simon Corbell said he would look at a bid for $90,000 funding made by the centre, but said the territory could not make up for the federal cuts being felt by a range of community legal centres.

On Wednesday, federal and state governments committed $30million for a domestic violence awareness campaign, while the federal government helped launch a new smartphone app to give vulnerable women information.

Opposition Leader Bill Shorten called for a national summit and said Labor would pledge $70million over three years for frontline services, perpetrator research, and home safety measures.

Prime Minister Tony Abbott said he wanted a bipartisan approach to the issue, and said better state coordination would be discussed in an upcoming Council of Australian Governments meeting.

Ms Brodtmann told parliament on Thursday that the nation needed to act urgently.

"We have to end this blight on our society," she said.

"We must do better and we must act now."

The GoFundMe page set up by friends after Ms Costigan's killing on Saturday is pushing to collect $100,000 from the Canberra community for her children.

The page is quickly reaching that goal, and had received over $76,000 by midday on Thursday.

That amount has been donated by friends, family, and complete strangers.

Donations have also come in from overseas.

The Costigan family has been in contact with the page's creator, Emma Luke, and say arrangements will be made to ensure every cent of the money goes to the children.

Ms Luke said earlier this week she had been surprised and heartened by the community's response.

"Everybody's touched by it. She has so many friends and other people who just want to help her kids at this time," she said.

The target was raised from $20,000 to $40,000 after the initial goal was reached within hours of accused killer Marcus Rappel's first court appearance on Monday.

A walk to honour Ms Costigan and stand against domestic violence is being organised for Sunday March 22, at 10.30am.

Thousands of people have registered their interest on Facebook and the event has rapidly gained support throughout the week.

Ms Costigan was allegedly murdered by her former partner Marcus Rappel on Saturday afternoon in Calwell.

She sought an interim domestic violence order against him on Friday.

Rappel will reappear in the ACT Magistrates Court later this month.