Christie, 18, died in her mother's arms after a violent attack at their North Shore family home in November.
"I can never describe what it has done to me but my heart shattered beyond repair," Mrs Marceau said.
"People handle grief in different ways. The determination and spirit of my angel Christie was so strong that I knew I had to be her voice and fight for what she could not.
"Within weeks of her being taken from us we set up a group called Christie's Law. Christie is working her magic because people are listening."
Ms Marceau said supporting White Heart Day was to offer remembrance "for those courageous loved ones that have been taken so cruelly before their time".
The day was organised last year by the family of Phil Cowan, who was murdered in 2001.
White doves were released by the families of victims at the different ceremonies.
Caroline Longley, whose daughter Emily was killed by her boyfriend Elliot Turner in England last year, said it was helpful to speak with people who understood her grief.
Ms Longley joined the release of doves in Auckland.
"You have to learn to celebrate their life and you have to know that they're in a better place," she said.
"I'm happy that she's safe and protected from any more evil happening to her."
In Wellington, Victim Support chief executive Tony Paine said tragedies like the Pike River disaster and Christchurch earthquake saw human support "at its very best".
He wanted to see similar remembrance events for victims of tragedy and crime, so the nation could come together to mourn the loss of loved ones and celebrate their lives.
"It is absolutely right and proper we take a little time out of our day, as we stand together."
Tyler McKelvey, who was 8-years-old when her cousin, Steven Stone, was murdered in 2007, today spoke of her love for her cousin.
"I love him with all my heart ... He was beautiful and funny."
Mr Stone was stabbed in his leg and heart by Andre Londale Watene after Mr Stone's flatmate handed over cannabis and $30 in a robbery.
The robbery was not being resisted.