"If you ask any planner, 'do you ever switch off', their answer would be, 'no'," she said.

"I'm counting how many people are waiting to get on the next stop, and imagining what the catchment is for that area and have they all got footpaths to the bus stop?"

The 34-year-old will now have a larger platform to put her thoughts into action as one of the 25 candidates confirmed on Saturday as successfully elected to the Legislative Assembly. More importantly, she was the third Labor winner in Yerrabi, one of a handful of victories which could not have been guaranteed before election day but allowed the party to remain in government.

"It's exciting, and the exciting part is the opportunity to get in and do something for the community," she said.

Community was not something Ms Orr had to go far to find growing up in Giralang. Her parents have fostered more than 200 children, with three permanent foster children she considered as siblings and up to eight children at once in the house. She was the only biological child.

She had always had friends in the Labor party, and was briefly in Young Labor, but it was not until 2013 that she re-joined, after complaining to her Labor friend about the shutting down of the unit she worked in with the then federal Department of Infrastructure and Transport.

"My friend's response was, 'If you want to do something about it why not join the party and get back involved?', and I thought he's right, why not get involved where the policy is made?" she said.

"For me it comes down to looking after people and the environment."

Her first lasting mark in politics was made championing the party's divestment of financial holdings in fossil fuels ahead of the annual conference last year. Ms Orr used her position as chair of the party's environment and urban infrastructure committee to gather support for the motion, called for by advocacy group 350.org, and Chief Minister Andrew Barr announced at the conference he was backing an amended plan.

Within three months, the government had divested nearly 45 per cent of its fossil fuel assets.

She converted her internal success into campaign backing, winning more first preference votes than any other Labor candidate in the five east Belconnen booths where she had grown up and her parents still live. A "horrible virus" which kept her at home for five days in the last week of campaigning didn't stop her being the fourth elected in the seat. She will hand in her resignation to the public service on Monday.

Ms Orr said she would "never say never" about a ministerial opportunity, with planning and environment a natural fit, but was "not expecting to go straight to the top".