Jill is a Distinguished Professor in the Wits School of Education. She is the former holder of a SARChI Chair in Mathematics Education at the University of the Witwatersrand, and former Director of the WMCS project. She has spearheaded several large-scale teacher development projects, the most recent of which is WMCS. This work builds on her research on teaching in multilingual classrooms, and teacher professional development. Jill is the 2017-2020 President of the International Commission on Mathematical Instruction (ICMI) and a Visiting Professor of Mathematics Education at King’s College London, UK. She is the recipient of numerous awards, the most significant of which are the 2012 Academy of Science of South Africa (ASSAf) Gold Medal for Science in the Service of Society, and the 2015 Freudenthal Award.