Dr. Freedman (born July 17, 1957) is easy to perceive as a successor to Allan Sandage in the field of cosmology. She had a disagreement of some standing with Sandage about what the eventual determination of the Hubble Constant would be. Sandage said it would be close to 50, Gerard de Vaucouleurs said it would be 100, and Freedman's eventual solution of close to 75 was supported by Hubble Space Telescope Cepheid data.

Freedman's studies up to her Ph.D. were at the University of Toronto. In 1980 she was the first woman astronomer to do an observing run with the Canada-France Hawaii Telescope. She also did visiting work during her studies at Mont-Mégantic, Las Campanas (UTSO and Dupont) and Kitt Peak (Mayall). The early-1980s work involved CCDs, although some follow-up work involved plate scanning. She received an Amelia Earhart Fellowship from Zonta International in 1981. She married fellow U of T astronomer Barry Madore in 1985, after a post-doctoral fellowship at the Carnegie Observatories in Pasadena. Soon after, she was the first woman on permanent staff at Observatories of the Carnegie Institution of Washington. She is now the John & Marion Sullivan University Professor of Astronomy and Astrophysics at the University of Chicago.

Freedman is often interviewed about the Hubble Constant and cosmology in general. As the director of Carnegie Observatories she was also the chair of the Giant Magellan Observatory organization, which plans to build a compound telescope of seven 8.5-metre mirrors on Cerro Las Campanas (By the end of 2021 the sixth mirror segment had been cast.)

Her first RASC lecture was to the Toronto Centre on 23 October 1981 on the subject of Evolution of Galaxies. Her first contribution to JRASC was in 1982. She gave a joint lecture at the Royal Canadian Institute and RASC Toronto Centre on 24 Jan 1993, 'Measuring the Size and Expansion Rate of the Universe'. She was the Helen Sawyer Hogg Lecturer at the 2000 General Assembly in Winnipeg, speaking about the Age and Size of the Universe. From 2005 to 2007 she was the honorary president of the RASC Toronto Centre.