Cate Faehrmann is the NSW Greens' new spokeswoman for the environment, women and a host of other issues after taking the Legislative Council seat of Mehreen Faruqi, who joined the federal Senate this week.

"I come to this role with a long history of environmental activism, so I am proud to take responsibility for the environment portfolio for the Greens," she said in a statement on Thursday.

"Other priorities for my term in parliament will include abortion law reform, a new approach to drugs, improving the rights of animals and finally making dying with dignity legal."

The new MP's path to the parliament took her via the Supreme Court, where she fought the NSW Greens for the right to nominate for the seat's preselection.

The court overruled the party's decision to list Ms Faehrmann as a "provisional" member after she transferred her membership from Victoria.

She was a member of the NSW Legislative Council from 2010 to 2013 when she resigned to make an unsuccessful bid for the federal Senate.

She then took a leadership role in Senator Di Natale's office.

Australian Associated Press