Marilyn is the eldest of five children born to the late George Ferreri of New York, a chemical engineer and former Director of the Air and Radiation Administration for the State of Maryland, and Mary Lynch Ferreri of Baltimore, a retired Baltimore County English teacher. Marilyn was born in Baltimore but spent her early years in New Jersey. After moving back to Baltimore at the age of 8, Marilyn attended St. Matthew's Parochial School and completed grammar school at the Institute of Notre Dame. After graduating from Western High School, she earned her Associates Degree in Nursing from Essex Community College cum laude. She completed a Bachelors degree in Nursing from the College of Notre Dame of Maryland, and then earned a Masters Degree in Business with a concentration in Management from Johns Hopkins University.

Marilyn met her husband, Dennis Booker, in their Northwood neighborhood. The couple dated throughout high school and they were married at Immaculate Conception Church in Towson. They have two children, Reed and Mary. The Booker family moved from their home in the Loch Hill section of Baltimore County to Sunnybrook in Jacksonville in 1990. Dennis works for the State of Maryland as an Administrator with the Department of Health and Mental Hygiene.

Marilyn has a successful career as a Registered Nurse. During her career, Marilyn has held a variety of nursing positions as a clinician and manager. Her clinical positions have included critical care and home care nursing. She has held a number of management positions including Nurse Manager, Regional Director of a Home Health and Staffing agency; the Executive Director of a Home Health agency, and the Director of Clinical Services and Quality Improvement for a Home Infusion Company. In addition, Marilyn spent several years arranging research for a European-based dietary supplement company as well as writing marketing and technical materials for them. In 1995, W.B. Saunders Com published InfusionTherapy, Techniques and Medications, for which Marilyn was the primary author. Marilyn has also contributed chapters for other nursing textbooks. Currently, she is working as the Director of Clinical Informatics at Good Samaritan Hospital, where she is involved in the implementation of Medstar Health Group's electronic documentation system.

2008 was a very good year for the Booker family. Not only did Marilyn decide to run for the House of Delegates, but Reed's wife, Allison, gave birth to Marilyn and Dennis' first grandchild, Jacob Reed Booker.