Whitelock is an astronomer at, and former director of, the South African Astronomical Observatory and an honorary professor at the University of Cape Town. She obtained her BSc and PhD at the University of London. Her primary research interests are the late stages of stellar evolution, mass-loss and variability. She also works on galactic structure, near-by galaxies and the cosmic distance scale. She is involved in astronomy education, astronomy for development, and international coordination and collaboration. She has served as president of the International Astronomical Union’s Division VII (Galactic Systems), is a member of the Academy of Sciences of South Africa, an honorary fellow of the Royal Astronomical Society (UK) and an honorary member and fellow—and former president—of the South African Institute of Physics (SAIP). She is the recipient of the 2018 de Beers Gold Medal of the SAIP, a Doctor of Laws (honoris causa) from Rhodes University in 2020 and member of TWAS since 2021.