Smith graduated in 1987 with a bachelor's degree in mathematics from Princeton University, where she was influenced in her freshman year by Charles Fefferman. She was a high schoolmathematics teacher in the academic year 1987/1988. In 1988 she became a graduate student at the University of Michigan, where in 1993 she earned her PhD with thesis Tight closure of parameter ideals and f-rationality under the supervision of Melvin Hochster. In the academic year 1993–1994 she was a postdoc at Purdue University working with Craig Huneke. In 1994 she became a C.L.E. Moore Instructor and then an associate professor at MIT. Since 1997 she has been a professor at the University of Michigan. In 1991 she married the Finnish mathematician Juha Heinonen who died in 2007.
Honors
In 2001 Smith won the Ruth Lyttle Satter Prize in Mathematics for her development of tight closure methods, introduced by Hochster and Huneke, in commutative algebra and her application of these methods in algebraic geometry. The prize committee specifically cited her papers "Tight closure of parameter ideals", "F-rational rings have rational singularities". In addition to the Satter Prize, Smith was the recipient of a 1997 Sloan Research Fellowship, a Fulbright award, and a University of Michigan Faculty Recognition Award for outstanding contributions as a teacher, scholar and member of the University community. Smith was selected to give the 2015 Earle Raymond Hedrick Lectures at the Mathematical Association of America's MathFest. Smith was chosen to give the Association for Women in Mathematics-American Mathematical Society 2016 Noether Lecture at the Joint Mathematics Meetings. In 2015 she was elected as a fellow of the American Mathematical Society "for contributions to commutative algebra and algebraic geometry." In 2019, she was elected to the National Academy of Sciences. The Association for Women in Mathematics has included her in the 2020 class of AWM Fellows for "her tireless support of women in mathematics; throughout her career, she has officially and unofficially mentored numerous female mathematicians at every level from undergraduate to full professor; she continues to be an incredibly strong role model for women everywhere".