Lai was born in
Ottawa, Canada, to parents who had emigrated there from Hong Kong; she moved to New Jersey with her family at age nine. She majored in mathematics at the
Massachusetts Institute of Technology, graduating in 2002. As an undergraduate, she was a coauthor on the proof of the four-dimensional case of the
double bubble theorem, on the optimal shape of two-chamber
soap bubbles. She completed her Ph.D. in 2008 at the
University of California, Davis, with the dissertation
An Effective Compactness Theorem for Coxeter Groups supervised by
Michael Kapovich. She joined the
University of Michigan from 2008 to 2011 as an NSF-RTG Assistant Professor. After continued postdoctoral research in mathematics education at the University of Michigan with
Deborah Loewenberg Ball and
Hyman Bass, she joined the University of Nebraska–Lincoln as an assistant professor of mathematics in 2013. She was the first tenure-track faculty member there focusing on mathematics education. She was given the Harold & Esther Edgerton Assistant Professorship in 2016, promoted to associate professor in 2019, and given the E. Mohr Associate Professorship in 2020. Lai was the founding chair of the Special Interest Group of the
Mathematical Association of America (MAA) on Mathematical Knowledge for Teaching, serving as chair from 2017 to 2019. She also chaired the MAA Committee on the Mathematical Education of Teachers from 2021 to 2024. ==Recognition==