Dr. Williams' research focuses primarily on reproductive and perinatal epidemiology. Over three decades, she has integrated epidemiological, biological, and molecular approaches into rigorously designed research that has advanced understanding of placental abruption, gestational diabetes, and preeclampsia. Her research methodology includes: (1) identifying literature gaps; (2) developing robust epidemiological data systems across North America, Sub-Saharan Africa, Asia, and South America; and (3) integrating biochemical and molecular biomarkers into these platforms. In 2019, in partnership with Apple Inc. and the National Institute of Environmental Health Sciences, she co-designed and currently co-leads the Apple Women's Health Study, a large-scale digital national study examining determinants of women's gynecological health. Dr. Williams has been recognized for her excellence in teaching, as the recipient of the 2015 Harvard Chan School’s Outstanding Mentor Award, the UW’s Brotman Award for excellence in teaching (2007), the American Public Health Association’s Abraham Lilienfeld Award for education in epidemiology (2007), and the White House’s Presidential Award for Excellence in Science, Mathematics, and Engineering Mentoring (2012).