In that position, she provided guidance and direction to the OAS member states and permanent secretariat on hemispheric policy advancing issues affecting women, particularly in the areas of human rights and gender equality.

She was an advisor on Hispanic Affairs to the White House Office for Women's Initiatives and Outreach, as well as search manager in the White House Office of Presidential Personnel during the 1996 presidential transition, where she worked on sub-cabinet appointments in the area of international trade.

She worked for Mayor Richard M. Daley as director of the Private Industry Council of Chicago and also implemented and managed one of the nation's most successful graffiti abatement programs.

In addition, she has extensive experience in the private sector, working for the Chicago-based Inland Steel Company in various sales and marketing capacities.

Lomellin has spent a major part of her professional career and personal life working on women's issues, particularly those in the United States Hispanic community.