[2][3] She was born in St. Johns, Michigan, in 1964,[2] but moved to Edmonton, Alberta with her family as a child.
She went to Ohio State University for graduate study in astronomy, completing her Ph.D. in 1992.
Her dissertation, A Study of Properties of Dark Galaxy Halos in a CDM Universe using N-body Simulations, was supervised by Jens Villumsen.
[2][4] After postdoctoral research at the California Institute of Technology and Los Alamos National Laboratory, she joined the Boston University astronomy department faculty in 1995.
[5] In 2023 the American Astronomical Society (AAS) named Brainerd as a Fellow of the AAS, "for pioneering work in the use of weak gravitational lensing to measure the structure of individual galaxies; significant service to the Society in committee roles and on the Board of Trustees; and leading the Institute for Astrophysical Research and the Department of Astronomy at Boston University to a significant expansion in research in observational astronomy".