Rachel obtained a PhD in Mathematics at the University of Exeter in 2010. Her thesis focused on spatiotemporal modelling of dengue epidemics in Brazil. She held postdoctoral positions at the UNESCO-IAEA International Centre for Theoretical Physics in Italy and the Catalan Institute for Climate Sciences in Spain, working at the interface of climate prediction science and public health decision-making. In 2017 she was awarded a Royal Society Dorothy Hodgkin Fellowship, which allowed her to create the Planetary Health & Infectious Diseases Lab at the London School of Hygiene & Tropical Medicine (LSHTM). Rachel now leads the Earth Sciences - Global Health Resilience group at the Barcelona Supercomputing Center (BSC). Between 2021-2024, she served as Director of the Lancet Countdown in Europe, a transdisciplinary collaboration tracking progress on health and climate change. Rachel is a member of the World Meteorological Organization's World Weather Research Programme (WWRP).

Rachel’s research involves modelling the impact of environmental change on infectious disease epidemics, to inform disease control and prevention strategies. She has published high impact research on modelling climate-sensitive disease risk, with a focus on integrating seasonal climate forecasts in dengue early warning systems in Latin America, the Caribbean and Southeast Asia. Her group works on diverse projects including disentangling the role of land-use change and socio-economic pressures on malaria resurgence in the Amazon, modelling zoonotic disease risk at the human-animal-environment interface, and understanding the role of climate, cities and spatial connectivity on dengue transmission regimes. In 2018, she won the International Society for Neglected Tropical Diseases Water Award for Research, in recognition of the quality of her research on the linkages between hydrometeorological extremes and dengue outbreaks and the multi-sectoral relevance for policy and practice.