Rosie Batty Photo: Alex Ellinghausen
A tearful Rosie Batty has marked the 13th birthday of her late son Luke with a new campaign that tells victims of domestic violence they are "Never Alone".
Luke was murdered by his father in February 2014.
"This would have been Luke's 13th birthday," Ms Batty told reporters.
"He would now be taller than me, his voice would be deeper, possibly he'd be shaving.
"I see his friends are all growing up and changing, and it is really hard ... (he was) captured in his youth."
She urged Australians to log on to website neveralone.com.au for the latest information on domestic violence, and also join the political campaign for change.
"Today is a day that will be unique to me, for no other mother had a son like my Luke. Yet sadly, it is also a day that will bring a pain tragically familiar to many other mothers: the birthday of a loved one lost to family violence," writes Batty on Never Alone.
"Since Luke was killed, I have faced a fundamental choice: rage against the senselessness of his death, or channel that energy and try to make it count for something. Luke was too special not to leave a legacy, and I am determined to forge one for him.
"I want us all to have uncomfortable conversations about the way family violence services are funded, and about the way the police and judicial systems deal with both the perpetrators and victims of this most pernicious crime."
Luke's murder during cricket practice at a suburban oval in Melbourne shocked the nation, and Ms Batty was named Australian of the Year 2015 for her advocacy on family violence issues.