Hi, I’m Dr. Melanie Vega, and I’m proud to bring deep clinical expertise and a thoughtful, holistic approach to pediatric care at Ollie.

I’ve always been drawn to science and medicine, knowing early on that I wanted to make a meaningful impact in children’s health. After earning my bachelor’s degree in psychology, I attended St. George’s University School of Medicine. I completed my clinical training in Miami at Jackson Memorial Hospital and Nicklaus Children’s Hospital, followed by a pediatric residency at Mercer University in Georgia, where I served as chief resident in my final year.

Because so much of pediatric care involves understanding and managing infections, I went on to complete a fellowship in pediatric infectious disease at the University of Florida in Jacksonville. I’m board-certified in general pediatrics and board eligible in pediatric infectious disease. This advanced training allows me to provide families with a higher level of insight, precision, and confidence—especially when it comes to complex or recurrent conditions.

What drew me to Ollie is our shared belief that exceptional pediatric care goes far beyond the exam room. I value a proactive, integrative approach that blends medical expertise with personalized attention. I believe in the power of nutrition, movement, mental wellness, and collaboration with trusted specialists to give each child their strongest foundation for lifelong health.

As a mom, I know how important it is to feel heard, supported, and confident in your child’s care. That personal perspective shapes the way I practice medicine—combining deep clinical knowledge with practical understanding and a true sense of partnership with families. My goal is for families to feel that they have a true partner—someone who takes their child’s health as seriously as they do.

Fun Fact
Half of my brain is science and the other half is art. I once dreamed of being an art curator and still have a bucket-list goal of appearing in a movie one day.

Hi! My name is Dr. Alejandra Sisniegas, Ollie’s primary care and child psychologist, and I love empowering children and parents to overcome difficult times. I am a fellowship trained psychologist, and I received my doctoral degree in Clinical Psychology from Nova Southeastern University in Fort Lauderdale, FL. I have worked with hundreds of families, children, and adolescents to address concerns related to behavior, development, anxiety, depression, ADHD, and adjustment to medical diagnoses.

My Style: Building a strong and trusting relationship with my patients is key! We all know it feels so good to be around people who are non-judgmental and make you feel comfortable – this is always my goal when I am in a room with a family. Ollie’s “Curious Mind” approach aligns with the “natural curiosity” that I bring when I work together with families to help them achieve their goals.

My Intervention Approach: Of course, my dedication to the families I serve is connected to my love for science and psychology. That’s why I went through many years of specialized education and training: To make sure I deliver quality, evidence-based care that is proven to give results! The integrated model of care at Ollie Pediatrics aligns with my philosophy as a clinician, as it is a model of healthcare that is not only highly researched but proven to produce better health outcomes for our patients and families.

My Training Background: I had the honor of completing my pre-doctoral internship at one of the top children’s hospitals in the nation – Children’s Hospital Colorado, where I served children, adolescents, and their families within an integrated primary care (IPC) setting. My training in IPC allowed me to work with pediatricians, nurses, psychiatrists, and other disciplines to provide comprehensive care. I witnessed science first-hand 😍, as I saw the benefits of prevention, early detection, and early intervention on the children and families that I worked with. This is one of the many reasons I am so excited to be an integral part of Ollie Pediatrics. You are the expert in your child, and I am the expert in child development and intervention – Let’s join forces to help your children and your family thrive!

Fun Fact
I love karaoke and am actually pretty good at it!!

Hi! I’m Dr. Giselle Garcia-Rivero, a proud mom of three wonderful kids and a board-certified pediatric nurse practitioner with over a decade of experience caring for children and families across South Florida.

My journey in pediatrics began at the University of Miami, where I earned my Bachelor of Science in Nursing. I spent my early years as a neonatal ICU nurse at South Miami Hospital—an experience that taught me the power of compassion, precision, and teamwork in caring for our tiniest patients. While there, I completed my Master of Science in Nursing at Florida International University, eventually earning my Doctor of Nursing Practice (DNP) from UM as well. Go Canes!

Over the years, I’ve had the privilege of serving families in a variety of specialties—pediatric oncology, cardiology, and primary care—each deepening my commitment to family-centered, culturally-sensitive care.

Today, I work in developmental and behavioral pediatrics at the UM Mailman Center for Child Development and am an assistant professor at the UM School of Nursing.

Through Ollie Pediatrics, I’m excited to bring high-quality, personalized care right to your doorstep. I love getting to know families where they feel most comfortable—at home—and partnering with parents to support their children’s growth and well-being.

Fun Fact
Outside of medicine, music has always been my creative outlet! I’ve been singing since childhood, performed with a cover band all through college, and even had the honor of singing the national anthem at Marlins games.