Her grandfather, Sir Percy Spender, was a Liberal MP under Prime Minister Robert Menzies, a diplomat and the president of the International Court of Justice.

In late 2021, Spender was approached by a local community group who were seeking an Independent candidate to run in the division of Wentworth at the 2022 Australian federal election.

[2] The group wanted a woman with "deep local roots and an impressive CV" who shared the community's core beliefs on the need for more integrity in politics, action on climate change and gender equality.

[2] After initially declining the approach, Spender announced her intention to run in November 2021, citing government inaction on climate change as one of the key reasons for her candidature.

[25] In her first fortnight in parliament, Spender secured amendments to strengthen the Climate Change Act by requiring sector-by-sector assessments of emissions reduction policies.

[26][27] During the course of the 47th parliament, she also played a key role in successfully advocating for the introduction of fuel efficiency standards for new vehicles,[28] funding to support household electrification, and greater private investment in nature protection.

[48] In October 2024, Spender resigned her membership of the Qantas Chairman's Lounge and the Virgin equivalent, saying it was time to end the practice of politicians accepting airline upgrades.

When the Labor Government announced in August 2024 that it would not include questions on LGBTQ+ identity in the next census, Spender was one of the leading advocates who successfully argued for the decision to be reversed and for LGBTQ+ people to be counted.

Since coming to office, she has reportedly held over 65 community events,[73] featuring the likes of tax expert Ken Henry, renowned playwright Suzie Miller, investigative journalist and author Jess Hill, Professor Tom Calma AO and Tim Buckley.

She has also held events with younger local influencers such as Anjali Sharma, Lottie Dalziel, Hannah Ferguson, Chanel Contos and Ruby Langton Batty.

Spender was a highly visible presence in the aftermath of the attacks, comforting local constituents at the site and leading tributes alongside Prime Minister Anthony Albanese and NSW Premier Chris Minns.

[77] As editor of the Good Weekend, Katrina Strickland commented: “After the Bondi Junction stabbings in April, I, like thousands of others, felt compelled to lay flowers at the impromptu memorial that had sprung up in the nearby shopping centre.

I found myself walking past regularly in the days that followed, bearing witness to the growing number of floral tributes, a life-affirming antidote to the darkness of the time.