Sarah Sobalvarro, PhD

Dr. Miller is a pediatric psychologist at Johns Hopkins All Children’s in St. Petersburg, Florida. She joined the hospital staff in 2024. She earned her doctorate in psychology from the Wright State University School of Professional Psychology in Dayton, Ohio. She completed a pre-doctoral psychology internship in the pediatric health track, followed by a postdoctoral psychology fellowship, at Nicklaus Children’s Hospital.

Dr. Johnston is a pediatric psychologist at Johns Hopkins All Children’s Hospital. She specializes in evaluating and treating behavioral health concerns (e.g., adjustment to illness, anxiety, treatment adherence, coping) among youth with cancer, blood disorders, and/or bone marrow transplant. Dr. Johnston sees patients in the Cancer & Blood Disorders Institute. She joined the hospital staff in 2025. Dr. Johnston earned her doctoral degree in clinical-community psychology at the University of South Carolina. She completed an internship in pediatric psychology followed by a post-doctoral fellowship in pediatric psychology with combined emphasis on hematology, oncology, bone marrow transplant, and research at Johns Hopkins All Children’s Hospital. Dr. Johnston’s research interests involve behavioral pain management, mitigating youth’s functional impairment, and understanding resilience factors to improve youth’s behavioral health outcomes.

Dr. Fritz is a pediatric psychologist in the Johns Hopkins All Children’s Institute for Brain Protection Sciences. She joined the hospital staff in 2018. Dr. Fritz provides evidence-based interventions for pre-school and early childhood disruptive behavior disorders.She also specializes in the evaluation and treatment of children and adolescents diagnosed with chronic and/or acute medical conditions in combination with additional concerns (e.g., anxiety, depression, treatment adherence, phobias) in outpatient settings.Dr. Fritz earned her doctorate in clinical psychology from the University of Florida. She completed an internship and then a post-doctoral fellowship in psychology at Texas Children’s Hospital/Baylor College of Medicine in Houston, Texas.