She was a member of Manhattan's Community Board 7 and Chair of the New York State chapter of the National Women's Political Caucus.

[4][better source needed] Brewer has helped to pass legislation protecting domestic workers, establishing the New York City Broadband Advisory Committee, establishing an electronic death registration system and requiring New York City publications to be made available via the Internet, as well as two bills aimed at eliminating graffiti and unwanted stickers.

[9] The report was one of numerous initiatives and events implemented by the Select Committee, which included roundtables, conferences, hearings, and collaborative partnerships.

[22] Brewer's main progressive Democratic primary challenger in 2021, Sara Lind, was not reappointed to Manhattan Community Board 7 when her position came up for renewal in 2023.

[23] She is a member of the Committees on Consumer and Worker Protection, Finance, Governmental Operations, Higher Education, and Rules, Privileges, and Elections.

[26] Brewer is a member of the Vote Blue Coalition, a progressive group and federal PAC created to support Democrats in New York, New Jersey, and Pennsylvania through voter outreach and mobilization efforts.

[27] In 2018, the Metropolitan College of NY awarded Gale Brewer an honorary doctorate citing her "long career on critical issues facing New York City from affordable housing and land use to health care and workers rights".