[3] Mitchell began her professional career as a teacher-director of a child care center in a low-income house development in Cambridge, Massachusetts.
In the early 1980s, Mitchell began working for the Bank Street College of Education, eventually becoming the Associate Dean of the Research Division, a post she held through 1991.
Mitchell's work has included national studies of state and local prekindergarten policy and early care and education finance.
In 2007, she received the Visionary Award from the National Louis University’s McCormick Tribune Center for Early Childhood Leadership.
Mitchell received the 2008 Excellence in Leadership award from the New York State Child Care Coordinating Council.