Pedersen was born in Salt Lake City, Utah, the daughter of an ophthalmologist and a teacher. She studied home economics changing to a double major in mathematics and physics as an undergraduate at Brigham Young University, before becoming a graduate student in mathematics at the University of Utah under the supervision of E. Allen Davis.^[2]

After completing her master's degree, she moved to San Jose, California, following her husband who worked for IBM. She joined the faculty at the Santa Clara University on a part-time basis in 1966, but shifted to full-time and was promoted to full professor in 1996. She was the first woman to teach mathematics at the university, and the first to be tenured as a mathematics professor.^[2]

Her discovery that the platonic solids could be braided from strips of paper led to Martin Gardner writing about it in the September, 1971 Mathematical Games column in Scientific American.^[3]

Pedersen's books include:

• Geometric Playthings (With Kent Pedersen, Dale Seymour Publications Secondary, 1973, ISBN 978-0866513517)
• Fear No More: An Adult Approach to Mathematics (with Peter Hilton, Dale Seymour Publications, 1982 ISBN 978-0201057133)
• Build Your Own Polyhedra (with Peter Hilton, Addison-Wesley, 1988)^[4]
• Mathematical Reflections: In a Room with Many Windows (with Peter Hilton and Derek Holton, Springer, 1996)^[5][6]
• Mathematical Vistas: From a Room with Many Windows (with Peter Hilton and Derek Holton, Springerl 2002)^[5][7]
• 99 Points of Intersection: Examples—Pictures—Proofs (by Hans Walser, translated with Peter Hilton, Mathematical Association of America, 2006)^[8]
• A Mathematical Tapestry: Demonstrating the Beautiful Unity of Mathematics (with Peter Hilton, illustrated by Sylvie Donmoyer, Cambridge University Press, 2010)^[9]

She and Peter Hilton also translated The Golden Section and Symmetry by Hans Walser from German into English. Both translations were published by the Mathematical Association of America in 2001.^[10]