Matthew Bennett
Matthew BennettMD
Dr. Bennett has practiced pediatrics in the Valley since 2001. Seeing the need for pediatricians in the southwest valley, he started Estrella Pediatrics in August 2005, shortly after the opening of Banner Estrella Medical Center. Raised in Wisconsin, he completed his undergraduate, graduate and residency training through the UW system and their academic campuses.
In addition to his busy office work schedule, he frequently helps out in the Emergency Department at Banner Estrella Medical Center during the busy cold and flu season.
Caroline Harper
Caroline HarperPA-C
Caroline Harper, PA-C joined Estrella Pediatrics in 2009. She has over 20 years of experience in pediatric and emergency medicine. Born and raised in Michigan, she earned a Bachelor degree in Health Science and Masters in Physician Assistant Studies, both from Grand Valley State University.
Physician Assistants diagnose and treat illnesses, write prescriptions, perform procedures and assist in surgery. They are licensed under the supervision of a physician. They are required to maintain their license by logging 50 hours per year of continuing education and passing a national board exam every 6 years.

It is easy to see Caroline loves caring for children and educating parents. She is passionate about nutrition and early literacy and has a special place in her heart for exhausted new mommies. As a mother of two she knows first-hand what a challenge and a blessing parenting is. This is obvious in the relationships she builds with our families. She spends her free time running marathons and hiking.

Carolyn Smeltzer
Carolyn SmeltzerFNP
Carolyn obtained her Master’s degree in nursing specializing in Family Nurse Practitioner from Vanderbilt University in 1992. Originally from the Chicago area, she and her family spent 15 years in Nashville before moving to Phoenix in 2007. Before coming to Phoenix, her previous experience was in pediatric anesthesia/pain management and child abuse. Since coming to Phoenix, she has concentrated on pediatric primary care. She has found working with children and families the most rewarding experience. Carolyn has been married for over 30 years and has twins, a boy, and a girl, that are now young adults. She enjoys cooking, hiking, rides on the back of a motorcycle, volunteering at church and in the community, and spending time with her family and 3 dogs.
Karen Grayberg
Karen GraybergC-PNP
Karen earned her Bachelor’s degree in nursing and her Master’s degree as a Pediatric Nurse Practitioner from Arizona State University. She is certified through the Pediatric Nursing Certification Board (PNCB) and is a National Association of Pediatric Nurse Practitioners (NAPNAP) member. Previously a member of the Estrella Pediatrics team, Karen returned in June 2023.
In her time off work, Karen enjoys spending time with her daughter and grandchildren, swimming, volunteering with the children at church, and playing with her two mini Goldendoodles.