She graduated from Glebe Collegiate and attended the University of Toronto for one year before marrying John Brewin in 1958.

Her parents and parents-in-law were all active in the CCF (Cooperative Commonwealth Federation), and founding members of its new version, the NDP.

Brewin began her political career in Scarborough, Ontario, when she was elected to the school board in the 1960s.

She and her family moved to Victoria in 1973 where husband John took a position with the NDP Barrett government.

[2] Brewin served as a NDP Member of the Legislative Assembly of British Columbia for the riding of Victoria-Beacon Hill from 1991 to 2001.