Our Providers
Our Physicians
David J. Cooper, M.D., Ph.D.
Born and educated (PhD) in the UK and moved to the US as a Grad Student (Molecular Biology). MD at age 38. Married, 5 children, all grown! I am an ‘outdoor’ person and a day on my bike in beautiful Lancaster County is always a delightful experience.
EDUCATION AND TRAINING
Graduated from Imperial College, London (PhD Organic Chemistry). 11 years in medicinal chemistry research (Schering-Plough, SmithKline). Then Graduated (MD) from the University of Miami Medical School and after pediatric residency/Clinical Pharmacology Fellowship, spent three years in Clinical Research (Merck, Lederle). Founded Chester County Pediatrics in 1978 and in practice since. Past 10 years developed strategies for implementing Telemedicine for Pediatrics.
PROFESSIONAL INTERESTS
Infectious Disease, Sports Medicine, General Pediatrics, Pediatric/adolescent Mental Health, ADD/ADHD, Telemedicine.
PERSONAL INTERESTS
Long distance biking, Photography, especially wildlife, Electronics, Flying, but aged-out!
Neil D. Pennington, M.D., Ph.D.
Joined Chester County Pediatrics, PC Fall 2022
Dr. Pennington completed his medical training in 1987 at the University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, where he was Chief Resident in Pediatrics. He then joined the Medical Staff of the Chester County Hospital, where he has served in many capacities, including Chairman of the Department of Pediatrics. He retired from the full-time Attending Staff at the Children’s Hospital of Philadelphia after 20 years of practice, and currently helps out part-time at local practices that are short-staffed, and also as a Hospitalist at smaller/rural hospitals in western Pennsylvania when needed.
He is on-call 24/7 as “Dr. Grandpa” for his eight grandchildren.
Spanish speaking families are welcome!
Our Nurse Practitioners
Caitlin Webb, CPNP-PC
Certified Pediatric Nurse Practitioner- Primary Care
Caitlin is a pediatric nurse practitioner who joined Chester County Pediatrics in 2013. She received her bachelor’s of science in nursing (BSN) and minor in psychology from Duquesne University in 2006. After college, she worked at the Children’s Hospital of Philadelphia as an RN until 2013 on an inpatient medical unit specializing in nephrology, adolescent medicine, and general pediatrics. In 2012, she earned her master’s of science in nursing (MSN) specializing in pediatric primary care from Villanova University.
Caitlin was a Division I athlete in college, competing on the women’s track and field team and remains interested in adolescent sports medicine.
Jessie Morrin, CPNP-PC
Certified Pediatric Nurse Practitioner- Primary Care
Jessie is a pediatric nurse practitioner who joined Chester County Pediatrics in 2017. She received her BSN in 2014 and her MSN in 2016 from Columbia University, specializing in pediatric primary care. Prior to becoming a nurse, Jessie graduated with a BA in Policy Studies from Lafayette College, where she rowed for the crew team. She is a member of the National Association of Pediatric Nurse Practitioners.
She loves baking and baseball, and is good friends with Doc McStuffins.
Lisa Rosaio, CPNP-PC
Certified Pediatric Nurse Practitioner- Primary Care
Lisa joined Chester County Pediatrics in March 2024. She graduated from University of Delaware in 2014 with her BSN and Thomas Jefferson University in 2022. As a nurse, Lisa worked in the PICU at both CHOP and Nemours, caring for critically ill children. After graduating from Thomas Jefferson, she worked as a nurse practitioner with CHOP’s hematology department.
Brenna Dunleavy, CPNP-PC
Certified Pediatric Nurse Practitioner- Primary Care
Brenna is a pediatric nurse practitioner who joined Chester County Pediatrics in 2024. She received her bachelor’s degree in nursing from WCU in 2017 and her master’s degree in nursing from Villanova University in 2023. She started her nursing career working with children requiring organ transplants prior to ultimately switching to primary care.
Before beginning her nursing career, Brenna graduated from USC with a major in sociology and a minor in communication sciences and disorders. She was co-captain of the club cheerleading team during college.
In her spare time, she enjoys yoga, and spending time with her family (including her fur babies) and friends. She grew up in Downingtown and loves that she can now give back in her own community.
Our Office Administrator
Brenda Souder, R.N.
Brenda was the first office nurse to work for Chester County Pediatrics at its inception in 1980. Since that time, she has worked tirelessly to bring the Practice to where it is today. In 2004, she was made a partner in the Practice.