[18] In 2016, Allen was involved in research undertaken at MCRI which described a link between Asian migration to Australia and increased risk of food allergy.

[20] Outside of her research, Allen has served as chair of the Melbourne Girls Grammar school council and as a director of Cabrini Health, a non-profit Catholic healthcare service.

[21] Allen was the Liberal candidate in Prahran at the 2018 Victorian state election, losing to the incumbent Greens MP Sam Hibbins.

[23] In February 2019, Allen won preselection for the Division of Higgins, replacing the retiring Liberal MP Kelly O'Dwyer.

[28] Allen visited PNG in August 2019 as part of a Parliamentary tour hosted by the Save the Children and Gates Foundation in the context of the Morrison government Pacific Step.

[41] In 2019, she wrote an opinion piece in The Sydney Morning Herald called "Keep an open mind about nuclear power for our carbon-neutral future".

[50] On 10 February 2022, Allen crossed the floor with four other Liberal MPs for an amendment to the Sex Discrimination Act to include protection for transgender students.

However, reports said that Allen, together with fellow Liberal MP Dave Sharma, agreed to only cross the floor if their votes would not be decisive in defeating the Government on the issue.

[51] Allen did not join fellow Liberals Trent Zimmerman and Bridget Archer in crossing the floor against the bill's controversial statements of belief clause.

[54][better source needed] Her husband works as a consultant and advisor across industries including finance, oil and gas, mining and private equity.

[5] Allen has said that her advice to women juggling work and family is to pay for help, saying "don't be proud, get help", and "not everyone has that privilege, but at the end of the day, you do need to make that financial decision".