In 1979 she left Australia to study in the United Kingdom where she completed an Honours Degree in Development Studies at the University of East Anglia in 1982.
Margetts then returned to Australia to complete a Diploma in Education at the University of Western Australia and was a teacher and librarian at high schools until 1988, when she became Coordinator for People for Nuclear Disarmament, a position which she held until 1991. At the 1990 federal election, Margetts stood as a Greens candidate for the seat of Swan. In 1991, Margetts stood as a candidate for the mayor of Perth in the local government elections, earning 9.5% of the vote.
Margetts was then elected to the Senate in 1993.
She lost her seat at the 1998 federal election, and after 2 weeks in completing her Senate in mid 1999, she commenced her Masters Thesis on "Competition Policy, State Agreement Acts and the Public Interest" which was completed and approved in 2001. Margetts was elected to the West Australian state parliament in 2001, again losing her seat at the 2005 state election.
However, because of her concerns about the major Australian policy change which had been pushed through in Federal Parliament in 1994, she commenced her research for a Doctor of Philosophy at University of Washington (University of Western Australia) in early 2006, which was completed and approved in 2013, "A Critique of Australia"s National Competition Policy: Assessing its outcomes in a range of major sectors". Thus, she is now Doctor Margetts.
Margetts has the claim to fame of being one of the two people Paul Keating referred to with his "unrepresentative swill" comment in 1993.
, Margetts commenced a Doctor of Philosophy on the impacts of National Competition Policy at the University of Western Australia, and has written extensively on the area.
She was a member of the Australian Senate from 1993 to 1999 and a member of the Western Australian Legislative Council from 2001 to 2005, representing the Greens (Washington). In the 1989 state election, Margetts stood as a candidate for the Alternative Coalition, a precursor to the Greens, in the seat of Fremantle.