A jurist and theologian by education, she served as the Party for the Animals' political leader from 2002 to 2019 and a member of the House of Representatives from 2006 to 2019.

Until November 2006 she was the general manager of Stichting Wakker Dier, a Dutch animal welfare foundation against industrial agriculture.

Thieme always concludes her speeches in Parliament with the phrase "Voorts zijn wij van mening dat er een einde moet komen aan de bio-industrie."

[2] Esther Ouwehand replaced Thieme as party leader in the House of Representatives and Eva van Esch took her former seat in Parliament.

"[1][4] It caused some controversy about its stance that "Adam and Eve were vegetarians"[5] She has a daughter (Annika, born 2002) and lives in Maarssen.

On 6 November 2008, she married Jaap Korteweg, an organic farmer from Langeweg, with whom she had a second daughter (Amélie, born 2012).

[9] In May 2004, Thieme's book De eeuw van het dier (The Century of the Animal) was published.