Women's Entrepreneurship and Economic Empowerment Act of 2018 This bill requires the U.S. Agency for International Development (USAID) to ensure that gender equality and female empowerment considerations are integrated into its strategies, projects, and activities. The Foreign Assistance Act of 1961 is amended to expand USAID microenterprise assistance authorities to include programs for small and medium-sized enterprises, particularly those that serve and are owned and managed by women. The bill revises requirements for the measurement of poverty levels by implementing partners. It also authorizes the establishment of a USAID office to support efforts to broaden local financial markets and support the development of micro, small, and medium-sized enterprises. The Government Accountability Office shall report to Congress on USAID assistance for such enterprises.