After leaving Parliament, she has worked in the public service, as deputy director of The Helen Clark Foundation, and as a writer and book reviewer.

[8] In September 2005 Critic's annual "Offensive Issue" included a fictional diary of a man who used drugs to stupefy and rape women.

In that speech, she acknowledged former co-leader Rod Donald as inspiring her early political activism when she viewed, at high school, a documentary about the 1981 Springbok Tour protests.

[16]From 2011 to 2014, Walker was the Green Party spokesperson for housing, electoral reform, children, open government, arts culture and heritage, and students.

[24] Three months before the 2014 general election, Walker withdrew from the Green Party list, citing "a recent unexpected change in my family life".

[28] Walker's memoir, The Whole Intimate Mess: Motherhood, Politics, and Women's Writing, published in 2017 revealed that the reasons for her retirement were "post-natal anxiety, a chronically ill husband, and domestic unrest.

"[29] After stepping down as a Green MP, Walker worked at the Office of the Children's Commissioner, and began a blog reviewing books written by women.

[31] In 2016 she launched a parenting podcast, Dear Mamas, co-hosted with Emily Writes, and contributed book reviews to Radio New Zealand's Nine to Noon programme.

It describes Walker's experiences while trying to combine motherhood and her career as an MP, including post-natal depression and instances of intentional self-injury.

[29] With Kathy Errington, the former executive director of The Helen Clark Foundation, Walker edited a collection of essays, Reconnecting Aotearoa: Loneliness and Connection in the Age of Social Distance, which was released by BWB in November 2023.