Our Leadership Team

At Children’s Memorial Hermann Hospital, providing the highest quality health care to our young patients and their families is our top priority. To do that, we hire the best. Our affiliated physicians, nurses, hospital staff and every other member of our team reflect our high standards of care. Our executive leadership team is another example of these high standards. Each member of our leadership team is highly qualified and respected in the fields of health care, exemplary patient care as well as best-in-class hospital operations.

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Marissa Kiefer

Senior Vice President and Chief Executive Officer, Children’s Memorial Hermann Hospital

Marissa Kiefer serves as Senior Vice President and Chief Executive Officer of Children’s Memorial Hermann Hospital, a 310-bed quaternary care women’s and children’s hospital with more than 40 specialties, including renowned programs in pediatric neurosciences, pediatric and congenital cardiac care, and pediatric trauma. In her role, Kiefer leverages her strategic mindset and passion for maternal and pediatric care to enhance operational performance across multiple service lines. In addition, she oversees a multidisciplinary team of health professionals to provide the highest level of care to women and children – including the latest advances in high-risk pregnancy and neonatal critical care – across the region.

Kiefer has more than two decades of experience and has held senior leadership positions at nationally recognized health care institutions, including Riley Children’s Health in Indianapolis and Children’s National Hospital in Washington, D.C. She is Lean Six Sigma Green Belt certified, a Tobias Leadership Fellow and a Carol Emmott Fellow. Kiefer holds a master’s degree in health services administration from The George Washington University and a bachelor’s degree from Indiana University in Bloomington, Indiana.

A community advocate at heart, prior to her relocation to Houston, Kiefer served as a founder and board member for GiGi’s Playhouse in Indianapolis and the Ronald McDonald House Charities of Central Indiana.

Outside of work, Kiefer enjoys spending time with her husband and three children.

Sean C. Blackwell, MD

Chief of Service, Obstetrics and Gynecology, Children’s Memorial Hermann Hospital; Professor and Chair, Department of Obstetrics, Gynecology and Reproductive Sciences

Dr. Sean Blackwell is the Chief of Service for Obstetrics and Gynecology at Children’s Memorial Hermann Hospital. In this role, he has been instrumental in developing a robust obstetrical and gynecological program at McGovern Medical School at UTHealth and in the Memorial Hermann Health System. Dr. Blackwell drove the development of The Fetal Center, and has aggressively expanded the high-risk pregnancy clinics throughout the Greater Houston area, now with nine clinic locations across the city. Under his leadership, the department of Ob/Gyn has developed a team-centric approach anchored in collaboration and a dedication to serving patients, as well as excellence in medical education and research.

Dr. Blackwell has been the principal investigator for Eunice Kennedy Shriver National Institute of Child Health and Development (NICHD) Maternal Fetal Medicine Units Network at McGovern Medical School at UTHealth (2007-2011), which is the largest clinical trials network in the United States. UTHealth is one of only eight institutions that have both the NICHD-funded maternal and neonatal research networks. In 2014, Dr. Blackwell earned his Six Sigma-Lean Black Belt at the University of Houston, allowing him to apply continuous quality improvements in operational processes to achieve predictable and measurable results.

He directs the Larry C. Gilstrap M.D. Center for Perinatal and Women’s Health Research at UTHealth and serves as the assistant dean for Healthcare Quality in Perinatal Medicine and Women's Health. He is a graduate of the Physician Quality and Safety Academy at Memorial Hermann-Texas Medical Center and McGovern Medical School at UTHealth. Blackwell served as the vice chair for the Society of Maternal Fetal Medicine (SMFM) Publications Committee and on the SMFM board of directors.

Dr. Blackwell obtained his undergraduate degree as a double major in biology and classics at Wabash College in Crawfordsville, Indiana. He completed medical school at the University of Illinois College of Medicine in 1993 and completed both his obstetrics and gynecology residency and maternal-fetal medicine fellowship at Wayne State University in Detroit, Michigan.

Kevin P. Lally, MD

Surgeon-in-Chief, Children’s Memorial Hermann Hospital; Professor and Chairman, Department of Pediatric Surgery

Dr. Kevin Lally is the Surgeon-in-Chief at Children’s Memorial Hermann Hospital and the Chair of the Department of Pediatric Surgery at McGovern Medical School at UTHealth. In his role, he has built and recruited for the hospital’s pediatric specialty services and continues to expand the programs within the surgical program, including General and Thoracic Pediatric Surgery, Pediatric Plastic and Craniofacial Surgery, Pediatric Neurosurgery, Pediatric ENT, Pediatric Cardiovascular Surgery, Pediatric Orthopedic Surgery, Pediatric Urology and Pediatric Trauma.

Board certified in pediatric surgery, surgical critical care and general surgery, Dr. Lally’s clinical interests include prenatally diagnosed problems and congenital diaphragmatic hernia (CDH) as well as Extracorporeal Membrane Oxygenation (ECMO). Dr. Lally, who has published more than 200 scientific articles with over 70 about basic science and clinical research on CDH, helped found the CDH Study Group and the CDH Registry. The voluntary collaborative has gathered data on more than 9,000 babies with diaphragmatic hernia. The registry now represents centers in 14 countries.

Dr. Lally is a distinguished graduate of the US Air Force Academy and an AOA graduate of Tulane University Medical School in New Orleans, Louisiana. He completed his residency at the United States Air Force Medical Center at Keesler Air Force Base, Mississippi, and a fellowship at Children’s Hospital of Los Angeles. Dr. Lally holds the Richard Andrassy, MD, Endowed Distinguished Professorship and the A.G. McNeese Chair in Pediatric Surgery at McGovern Medical School at UTHealth. He has been recognized by the Houston Surgical Society with the Distinguished Houston Surgeon-of-the-Year award, with UTHealth’s President’s Award for Mentoring Women, as well as UTHealth’s Teaching Excellence Award and Outstanding Surgical Educator award. He is a member of the American Pediatric Surgical Association, the American Academy of Pediatrics and is a fellow of the American College of Surgeons (ACS) and serves on the Advisory Council for Pediatric Surgery. 

Mary E. Aitken, MD, MPH, FAAP

Pediatrician-in-Chief, Children’s Memorial Hermann Hospital and Chair, Department of Pediatrics, McGovern Medical School at UTHealth

Dr. Aitken is Pediatrician-in-Chief at Children’s Memorial Hermann Hospital and Chair of the Department of Pediatrics at McGovern Medical School. Dr. Aitken joined McGovern Medical School in 2019 with the goal of building on the tradition of clinical and educational excellence of the pediatrics program, which combines quality-focused, cutting-edge care at Children’s Memorial Hermann Hospital and a network of primary care training sites and subspecialty pediatric clinics, including UT Physicians, across the Houston community. She is expanding the research capacity of the department to include not only basic and clinical science, but with a focus on population health for children. Dr. Aitken holds the Dan L Duncan Distinguished University Chair in Pediatrics and serves on the Clinical Leadership Council Governance Committee for UTHealth.

Dr. Aitken is a board-certified pediatrician who has devoted much of her career to the study and promotion of injury prevention for children. In her previous appointment at the University of Arkansas for Medical Sciences, Dr. Aitken was professor of pediatrics, interim president of the Arkansas Children’s Research Institute, vice chair for research for the University of Arkansas for Medical Sciences Department of Pediatrics, and interim section chief of General Pediatrics. She also led the Center for Applied Research and Evaluation from 2006 through 2019 and directed the Injury Prevention Center at Arkansas Children’s Hospital.

Dr. Aitken received funding from the National Institutes of Health, Centers for Disease Control and Prevention, and other federal, state, and private agencies to support her injury prevention research in motor vehicle safety, all-terrain vehicle (ATV) safety, and safe sleep in high-risk populations. Her clinical, educational, and advocacy efforts have been focused on prevention as well as treatment of acute and chronic conditions of childhood.

A graduate of the University of North Carolina School of Medicine, Dr. Aitken completed a pediatrics residency at The Johns Hopkins Hospital. She also completed a master’s degree in public health with a concentration in epidemiology during a general academic pediatrics fellowship at the University of Washington. She is the recipient of numerous awards including the Fellow Achievement Award of American Academy of Pediatrics Council on Injury, Violence, and Poison Prevention. She is a Fellow of the American Academy of Pediatrics and a member of the Society for Pediatric Research, American Pediatric Society, and the Society for Violence and Injury Research.

Emily Weber, DNP, RN, CPN, NEA-BC

Vice President and Chief Nursing Officer/Operations, Children’s Memorial Hermann Hospital

Dr. Emily Weber is the Chief Nursing Officer and Vice President of Operations at Children’s Memorial Hermann Hospital, a 330-bed quaternary care women and children’s hospital that is located at the Texas Medical Center campus. Children’s is a designated Level IV maternal care facility and Level IV NICU, which offer the highest level of comprehensive care for women and premature, sick and critically ill newborns.

With over 20 years’ nursing experience, Dr. Weber is passionate about high-quality, compassionate patient care and excellence in nursing leadership. In her role, she is responsible for advancing nursing practice, improving operational performance and ensuring compliance to the highest professional standards of patient care. She defines leadership as “Dream big, work hard and serve others,” and she leads by example while working to ensure individuals under her leadership feel supported in their own professional growth.

Dr. Weber received her Associate Degree in Nursing from Alvin Community College and her Bachelor of Science in Nursing from The University of Texas Medical Branch. She went on to complete her Master of Science in Nursing from Texas Woman’s University and finally her Doctor of Nursing Practice from UTHealth Houston. She is board certified in pediatrics and nursing administration-advanced. Prior to her role as the CNO of Children’s, she served as the CNO at HCA Houston Healthcare Southeast. She also held numerous leadership positions during her 20-year tenure at Texas Children’s Hospital, advancing from staff nurse to nursing director of general pediatrics, the Neonatal Intensive Care Units/Newborn Center and the Magnet Program Director.

Dr. Weber and her husband, Jeff, have two daughters. Jordan is currently a student at Texas A&M and their youngest, Lauren, stays active in competitive volleyball. Outside of work, Dr. Weber enjoys spending time with her friends and family and loves running.