Stiff-Roberts completed her bachelor's degree in physics at Spelman College in 1991. She was part of a NASA and Spelman College Women in Science and Engineering program. Through this progem, Stiff-Roberts worked as an intern at Ames Research Center during the summer. She then joined the Georgia Institute of Technology, where she earned a Bachelor of Engineering in 1999. She moved to the University of Michigan for her graduate studies, during which she investigated quantum dot photodetectors, gaining her PhD in 2004. She was a member of Phi Beta Kappa. She was funded by the David and Lucile Packard Foundation Graduate Scholars Fellowship and AT&T Labs Fellowship. She was also awarded the Burroughs Wellcome Fund.