Rosemary was born in Mineola, New York in 1959. She earned her Bachelor of Arts degree from Adelphi University in 1981 and her Juris Doctor from St. John's University School of Law in 1984.
She was admitted to New York State Bar and the United States District Court, Eastern and Southern Districts of New York in 1985.
She is a former Adjunct Professor of Graduate Business Law at Adelphi University. As an attorney, her memberships include Nassau County, Nassau Suffolk Trial Lawyers, New York State, and American Bar Associations. She is also a Member on the Board of Regents, Winthrop University Hospital.
She is one of the founding chairs for the annual outing that benefits the Winthrop University Hospital Cancer Center for Kids.