Our Physicians

David J. Cooper, M.D., Ph.D.

Born and educated (PhD) in the UK and move 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.


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.


Infectious Disease, Sports Medicine, General Pediatrics, Pediatric/adolescent Mental Heath, ADD/ADHD, Telemedicine.


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 1987at 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 & Physician Assistants

Caitlin Webb, CPNP-PC

Certified Pediatric Nurse Practitioner- Primary Care

Caitlin is a pediatric nurse practitioner who joined Chester County Pediatrics in the spring of 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.  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.   She lives with her husband, 2 schools aged daughters, and 2 rescue cats.

Jessie Morrin, C.R.N.P.

Jessie Morrin, CPNP-PC

Certified Pediatric Nurse Practitioner- Primary Care

Jessie is a pediatric nurse practitioner who joined Chester County Pediatrics in June of 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.


Adrienne Law- Kurpinski, CPNP-PC

Certified Pediatric Nurse Practitioner- Primary Care

Adrienne joined Chester County Pediatrics in April 2024. She graduated from Immaculata University with her BSN in 2002 and Drexel University with her MSN in 2021. She worked briefly at Chester County Hospital, then spent the next 21 years working at Nemours, specializing in cardiology. After she graduated from Drexel, she worked as a nurse practitioner in cardiology at Nemours as well as at a Penn State pediatric walk in clinic.




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.



John Buchheit PA-C

Physician Assistant

John joined Chester County Pediatrics in July 2023. John joined Chester County Pediatrics in July of 2023. He received his Bachelor’s degree in Biology/Premedicine with a minor in Spanish Linguistics in 2019 from Miami University of Ohio and completed his Master of Physician Assistant Studies from Mount Saint Joseph University in 2023. Prior to PA school, he worked as an EMT and a scribe in the ER during COVID.

He has traveled to 24 countries, loves birdwatching, and enjoys eating his wife’s delicious, home-cooked meals.


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.