The Canberra mechanic will take the next step in her Olympic journey when she captains the Australian women's sevens team in its World Cup title defence in Moscow on Saturday.

But just five years ago Williams was chasing her hockey dreams and moved to Canberra to try to break into the Australian squad.

Hockeyroos legend Nikki Hudson was her idol. She won an essay competition in 2004 to carry the Olympic torch before the Athens Games with two-time gold medal star Alyson Annan.

At that stage, Williams didn't even know there was an Australian women's rugby team.

''Mum and dad wouldn't let me play any contact sport when I was growing up. They didn't want me to get hurt,'' Williams said.

''So all I dreamt of when I was a little kid was playing for the Hockeyroos at an Olympics. I moved to Canberra and got picked in a Hockeyroos squad.

''But then one of my friends asked me to come to rugby training and after one game I was in the Australian team. The same year I was playing at a World Cup. I don't even have words to describe it.''

Hockey has taken a back seat for Williams with sevens being added to the Olympic program for the Rio Games in 2016.

The 25-year-old played one season with the Canberra Strikers and suited up next to Anna Flanagan who was named last week as the world's best junior player and played at the Olympics last year.

But while she grew up with a hockey stick, Williams has always wanted to be in a contact sport.

''I used to pretend to be [NRL star] Benji Marshall on a Friday afternoon at school playing against the boys. They could only tag me but I could tackle them,'' Williams said.

''Mum is still worried about me getting injured. I used to wear bright boots so she could see me get up if I got hit. But now I just have a bright mouthguard.''

Williams' rise to the top started in Canberra after joining Royals.

She juggled being a mechanic with her rugby duties and moved to Brisbane at the start of the year to be part of the full-time sevens program leading into the Olympics.

Her escape from rugby is fixing cars. Even when she was unemployed she would ask her housemates if she could work on their cars just to keep her busy.

It's that work ethic that has cemented her place in the Australian team and she hopes she can hold on to her place for another three years.

''Leading by example is what I do best. It still hasn't sunk in that I'm captain of the Australian team,'' Williams said.

''I got a job the same day that I was told I was captain of the World Cup team. I've been working since I was 16 years old, I just want to fix cars and play rugby. But for now I'm looking to the Olympics and it's crazy to think about.''

Australia will play South Africa, China and Ireland in their World Cup group.

They open their campaign against China before going into the knockout stages on Sunday.