Valentine was born in Philadelphia. During junior high she joined the Philadelphia Regional Introduction for Minorities to Engineering (PRIME) program, which prepared her for a career in physics or mathematics. She attended high school at Murrell Dobbins Vocational School, graduating in 1992. She completed a bachelor's degree in physics at Florida A&M University, which she graduated cum laude in 1996. Whilst at FAMU she was a "Life-Gets-Better" scholar, which allowed her to work as a summer research assistant at Lawrence Livermore National Laboratory. She also worked in the Center for Nonlinear and Nonequilibrium Aeroscience. Upon graduating from Fame, she moved on to Brown University for her postgraduate studies, earning a master's degree in 1998. Valentine studied under Chia-Ling Chien at Johns Hopkins University, where she worked on spintronics. Her research focused on novel rare earth metals for memory applications. She successfully defended her dissertation, "Spin Polarization Measurements of Rare Earth Thin Films", in 2006.