At least here in the U.S., the term would be Councilwoman/Councilman.

However, here in the U.S. Council members are not responsible for specific portfolios (at least not for any City Council I've ever heard of)... they all vote on issues, although may sponsor pet projects.

I know that's quite different in Spain, because a good friend of mine is a Concejala and has a specific portfolio.

Gender-neutral language is often preferred in English these days, so I propose Councillor for the translation, even though we know it is a woman. However, if you are using "Councilman" elsewhere, you should preserve "Councilwoman" here.

You could also say "City/Town Councillor for Equal Opportunity", but that sounds more like a voting position than a job function. I notice that in the following references, the reference to the city/town is dropped since it is assumed that the councillor is on the city/town council.

[DOC] IntroductionFile Format: Microsoft Word 2000 - View as HTML
Equal opportunity councillor. Interdirectional Coordinating Group. Coordinating Group Region-Province. EO Facilitator. Piedmont ...
www.retepariopportunita.it/HLG-on-Gen1/ riunione-2/organisational_relational_models_HLG.doc - Similar pages

[Gender Alp !] PP5 : Langhe Monferrato RoeroEqual Opportunity Councillor of the city of Cuneo - Economic Councillor of the city of Cuneo - technical consultant of Langhe Monferrato Roero ...
www.maisondutemps.asso.fr/genderalp/ article.php3?id_article=20&lang=en - Supplemental Result - Similar pages

This document shows a councilwoman having responsibility for equal opportunity: [PDF] MINUTES OF REGULAR MEETING HELD MAY 17, 2005File Format: PDF/Adobe Acrobat
MINUTES OF REGULAR MEETING HELD MAY 17, 2005. The Regular Meeting of The Borough Council of Washington, Warren County,. New Jersey was held in The Council ...
www.washingtonboro-nj.org/Council Minutes05-17-05.pdf - Supplemental Result - Similar pages