'Humanity on display' in tragedy's wake

Domestic violence campaigner Rosie Batty is proud to see the same outpouring of goodwill from Australians after the Sydney cafe siege as she experienced when her son was killed.

The kindness of the community gave her the strength to carry on after 11-year-old Luke was murdered by his father in February.

"Whether it's on television, whether it's personally, I have always noticed and really absorbed that kindness that humans and communities demonstrate through real tragedy," she told AAP on Wednesday.

"There's so much badness in the world but there is so much more good.

"Just like what's happening in Sydney at the moment, when there is great tragedy there is enormous community goodwill."

Ms Batty found courage from her family - courage represented by a small, blonde doll on display at the National Museum of Australia in Canberra.

Each 2015 Australian of the Year nominee was asked to lend the museum a personal object they felt represented their life and work.

Ms Batty, the Victorian finalist, thought of the doll her godmother gave her as a child shortly after her mother died.

It wears clothes knitted by Ms Batty's grandmother, Gertrude, who she describes as a very strong and inspiring woman.

South Australian peace campaigner Gill Hicks, who lost her legs in the 2005 terrorist bombings in London, said the Sydney attack showed it was important everyone recognised peace was something to actively strive for.

She has lent the gallery the briefcase she was carrying on the day of the bombings - an object she says marks the end of "life number one" for her.

The 2015 Australian of the Year will be announced in Canberra on January 25.

The National Museum's display will continue until February 28.