Speaking of the difficulties faced by modern families, she talked of the "changing nature of work" and how parents were trying to balance raising their kids with their careers.

"No one has yet worked out how to be in two places at once - so there are no simple solutions," she told the lower house in early 2010.

O'Dwyer's surprise exit from politics is testament to the fact there are no simple solutions. One of the Coalition's most senior women, last month she announced she would not contest the upcoming election because she wanted to spend more time with her young family.

In her farewell speech to the House of Representatives on Wednesday, the Minister for Jobs and Industrial Relations and Minister for Women said it was possible to have a family and serve at the "highest levels" but her priorities had shifted.

Waving to Olivia, 3, and Edward,1, in the public gallery, she said: "Livvy and Edward, you make my heart sing and I love you more than words can express. There is nothing that gives me greater joy than being your mum."

O'Dwyer joined the Liberal Party at 17 and was an adviser to former Treasurer Peter Costello, before winning his old seat of Higgins in a byelection in 2009.  Promoted to cabinet in 2015, O'Dwyer was the first female to sit in cabinet in a Treasury portfolio and in 2017, the first cabinet member to give birth.

"From the outside, politics looks like a brutal business - and it can be," O'Dwyer told the House.

"There is a ferocity and urgency that is a permanent overlay to everything that is said and done here. Because politics affects everyone."

O'Dwyer nominated her work helping to return the budget to surplus (as is predicted for the 2019-20 budget), tax cuts for small businesses and closing tax loopholes for multinationals among her key achievements.

While not a boat rocker on paper - coming from a blue-ribbon Liberal seat -  O'Dwyer nonetheless made a name for herself in Canberra as a relative radical: a Liberal woman who would actually use the term "feminist" and as one of the party's first public supporters of same-sex marriage.

O'Dwyer cautioned that her time in Parliament had coincided with a "deterioration of trust in both this institution and indeed, the very concept of democracy".

Arguing that social media and technology were speeding up and confusing political debate, the Jobs Minister said, "sometimes parliamentarians need to prosecute the case for patience and deeper conversation with their electorates".

O'Dwyer, a moderate, has previously been at pains to say she is not leaving Parliament because of the Liberal leadership spill last year. Along with praise for Prime Minister Scott Morrison's leadership, she gave a special shout out to former deputy leader Julie Bishop "for her friendship and guidance".  She also thanked former prime minister Malcolm Turnbull for his "friendship and great support of me when I gave birth."

While Mr Morrison and Treasurer Josh Frydenberg came to listen to their colleague's valedictory, the government benches were not full.

Beloved Labor figure Jenny Macklin, alternately brandished a tissue and chuckled with colleagues as she addressed the House for the last time on Wednesday.

A key cabinet minister during Labor's last term in government, and a former deputy leader to Kim Beazley, Macklin is Labor's longest serving woman in the lower house.

"Over 23 years in this place, I've quietly sobbed as good friends have said their own farewells. And now it's time for mine," Macklin said.

Macklin - who was minister for families, community services and Indigenous affairs during the Rudd-Gillard years - made her mark in social policy. She was instrumental to the introduction of headline reforms such as the government-funded paid parental leave scheme and the apology to the stolen generations. She was also minister for disability reform when the National Disability Insurance Scheme was introduced.

Macklin, who holds the Melbourne seat of Jagajaga, also spoke of the difficulties of combining Parliament and family.  "The hardest thing about political life has been the time I've missed with my children," she said. Macklin has three adult children, Josie, Louis and Serge.

Riffing on that famous Labor line, Macklin told the house, "It's time for me. Time to move on. Time to step back."