Ms Costigan, 28, was allegedly murdered by her ex-partner Marcus Rappel, 40, on Saturday in Calwell, after he forced his way into a home on Duggan Street.

Her killing has triggered a flood of condolences, messages of support for her family, and widespread condemnation of family violence from the Canberra community.

It has also seen a spike in requests for support and information to the Domestic Violence Crisis Service ACT.

Executive director Mirjana Wilson said many women had come forward for the first time seeking help.

"We've had quite a huge number of women come forward for the very first time... who have said 'I need help, I've just heard about this, this could be me, I've never spoken to anyone'," Ms Wilson said.

"So it has triggered a spike in people seeking support, and we'd continue to encourage that."

On average, two women are killed by a partner or ex-partner every week in Australia.

Ms Wilson said the more people sought help, the more that could be done to develop safety plans and minimise risk for them.

But she also warned the service could struggle to cope.

Their crisis intervention service has already had a 40 per cent increase in demand in the past five years, but has not received funding boosts for "quite a significant number of years".

Ms Wilson said it had left the service stretched, and only able to deal with the "pointy end" of family violence cases.

"On the one hand we want people to talk about it... we want to invite people to seek help," she said.

"But we want to provide them with a response that makes them feel heard and ultimately contributes to their safety in some way."

"We're 24/7 and uncapped so the best way I can describe it is like an emergency department in a hospital, you deal with what comes in."

The announcement of Rosie Batty, whose son Luke was killed by his father Greg last year, as Australian of the Year has helped refocus attention on the nation's family violence epidemic.

Ms Batty has called on the federal government to increase funding to community legal services and emergency relief grants that support victims of domestic violence.

She has also called for an end to victim blaming in family violence cases.

Ms Wilson said the current conversation about family violence was encouraging, but federal and territory governments needed to take real action.

"If governments are serious about national plans to reduce violence against women and children, and ACT strategies that do the same, it can't just be rhetoric and conversation," she said.

"It has to be backed up with supports and resources all the way through from primary prevention to crisis intervention and keeping people safe in the long term, and perpetrator programs."

The ACT's Domestic Violence Crisis Service has a crisis support line which operates 24 hours a day. It can be reached on 02 6280 0900.