Todd was born in Los Angeles, California, the daughter of producer George Eckstein and actress Ann Morgan Guilbert. She has a sister, Nora. Her parents divorced, and Guilbert married character actor Guy Raymond.
Todd is married to Glenn Withrow. She is the co-founder and Artistic Director of In House Media, a media production facility and acting conservatory devoted to training young actors. (http://www.positive-entertainment.com/interviews/hallietoddinterview.htm)