After earning her master's degree at the University of Florida, Bernadette worked in the advertising and promotions department of Castro Convertibles.

While raising her four children, Bernadette worked in the business on a limited basis and later moved into her role as the company CEO when they were grown.

She earned a master's degree in Education in Secondary School Administration in 1978 from the same institution and became the first woman ever to receive the university's College of Journalism Distinguished Alumnus.

In 1995, Bernadette was appointed Commissioner of the New York Office of Parks, Recreation and Historic Preservation by Governor George E. Pataki, a cabinet post she held for twelve years.

Among her many accomplishments as Commissioner, Bernadette worked with Speaker Newt Gingrich and the Trust for Public Land in 1996 to acquire the 18,000 acre Sterling Forest property for $55 million.

In 2001, President George W. Bush appointed Bernadette the Vice Chair of the Advisory Council on Historic Preservation.

In 2006, Castro established and strongly advocated an agreement by which Donald J Trump would construct a $40 million seaside dining and banquet hall at Jones Beach.

Trump's subsequent efforts to expand his facility proposal, coupled with increased opposition led to the project's cancellation.

In 2017, Bernadette was honored by the Franciscan Friars of the Atonement at their annual Sharing Hope Celebration Dinner with the Graymoor Award.

Bernadette acts as fundraising auctioneer for a number organizations, as well as the Master of Ceremonies for New York Presbyterian Hospital.