South Burlington Office


Karin Gray, M.D., F.A.A.P

Dr. Karin Gray grew up in Minnesota, studied biochemistry at Dartmouth, and then returned to her hometown to attend medical school at the Mayo Clinic. She completed residency at Cincinnati Children’s and was an attending hospitalist at Children’s National Medical Center in Washington, DC for several years. Looking for a place to raise their family, she and her
husband moved to Vermont in 2013. She spent the next ten years working as a hospitalist at UVMMC, where she also served as medical director of the newborn nursery. She is particularly interested in newborn medicine, quality improvement, preventative medicine, and complex care. In her free time, she enjoys skiing, hiking, and kayak camping with her family, as well
as reading and a little yoga.


Scott Cohen, M.D.

Dr. Cohen is originally from Bangor, Maine. He completed his undergraduate education at University of Vermont and his medical degree at Tufts University in 1989. He then moved to Oakland Children’s Hospital in California for pediatric residency and remained in the Bay Area for the next 33 years. His career included hospital pediatric medicine as well as outpatient primary care. He enjoyed teaching medical students and residents throughout his career in California. In 2002, Dr. Cohen
founded Global Pediatric Alliance, an NGO that trains indigenous midwives and health workers in remote parts of Latin America. Dr. Cohen’s clinical interests include global health, lifestyle medicine, and preventive care. In 2022, he moved to South Burlington with his wife and two children. He enjoys playing music, hiking in the Green Mountains, swimming, and winter sports.

Leah Costello, M.D., F.A.A.P.

Dr. Leah Costello grew up in South Burlington and received her undergraduate degree at Bates College in Maine. She attended the University of Vermont College of Medicine and then moved to Salt Lake City, Utah for her pediatrics residency at the University of Utah. Upon completing her residency, she spent four years as a general pediatrician in Salt Lake City. After the birth of their first child, she and her husband decided to return to Vermont to be near family and raise their children in this beautiful state. Before joining Timber Lane Pediatrics in the fall of 2016, Dr. Costello worked as a hospitalist at University of Vermont Children's Hospital. Dr. Costello enjoys caring for all children of all ages and has a particular interest in early childhood development, adolescent health care and quality improvement. She and her husband, who is a photographer, enjoy spending time with their son and daughter, alpine skiing, mountain biking, traveling and cooking for family and friends.  

Elizabeth Hunt, M.D., F.A.A.P.

Dr. Hunt, a native of New Jersey, studied community health at Brown University and then joined the Peace Corps.  She served in rural Ecuador as a public health volunteer for two years.  She completed her pediatric residency at UVM/Fletcher Allen Hospital and worked as a newborn hospitalist here at Fletcher Allen.  She was also staff physician at Woodside Juvenile Rehabilitation Center in Burlington, VT for two years.  Dr. Hunt then worked at the Mayo Clinic in Minnesota in general practice and as a newborn hospitalist.  She has experience in immunization research, urban public health outreach, speaks near-fluent Spanish, has volunteered in Haiti.  Dr. Hunt joined Timber Lane Pediatrics in 2011.  Dr. Hunt is particularly interested in breastfeeding medicine, infectious disease and children’s mental health and wellness. She enjoys spending time with her husband, Jesse Moore, a surgeon at Fletcher Allen, and their three young boys. She likes sailing, hiking and reading.

Monica Fiorenza, M.D., F.A.A.P.

Dr. Monica Fiorenza grew up in Burlington, VT.  As a child, she was a patient of Dr. Murray’s here at Timber Lane Pediatrics .  She graduated from Rice Memorial High School in South Burlington.  After completing her undergraduate degree in chemical engineering at Clarkson University in Potsdam, NY, she obtained her medical degree from the University of Vermont College of Medicine and completed her pediatric residency at the University of Rochester.  She spent time volunteering as a pediatrician on the island of St. Lucia before joining Timber Lane Pediatrics in 2003.  She lives with her husband, Dr. Gregory McCormick, and their 3 daughters in Hinesburg.  Dr. McCormick is an ophthalmologist with Ophthalmic Consultants of Vermont at 55 Timber Lane, right down the hall from Timber Lane Pediatrics.  She enjoys spending time with her family and friends, skiing at Mad River Glen, and waterskiing.

Gussie Logan, D.N.P., APRN, FNP-C

Gussie is a board certified Family Nurse Practitioner and a native Vermonter. She earned her Doctorate in Nursing Practice from the University of Vermont in 2019 while working as an RN at Timber Lane Pediatrics. Gussie then practiced as a NP for two years at a pediatric practice in Southern Vermont before returning to Timber Lane Pediatrics in the fall of 2021. She enjoys spending time with her husband and baby, being active outdoors, running, biking, hiking and is an avid baker. Gussie always knew she wanted to care for the pediatric population and finds her strengths are making connections with patients and families

Katherine Margulius, P.A.

Katharine (Kate) Margulius, PA-C, has been a practicing physician assistant since 2000.  She joined our practice in June 2009.  She graduated from the University of New England in Southern Maine as a physician assistant with a Master of Science degree.  Kate is licensed by the State of Vermont and certified by the NCCPA.  She enjoys caring for families with children of all ages and has special interests in women’s health, adolescent and college health.  Her non-working hours are spent with her husband, parenting their 3 children and spending as much time as possible outdoors.

Leah Macaulay, P.N.P, I.B.C.L.C.

Leah Macaulay, PNP, has worked in pediatrics in Vermont for over 10 years. She completed her nursing degree at UVM in 2007 and went on to Boston College to become a Certified Pediatric Nurse Practitioner. Leah is a board-certified lactation consultant with a special interest in breastfeeding infants.  Leah believes in a family-centered approach to caring for children. She loves working with children and families of all ages. Leah has a special interest in newborn care and lactation as well as pediatric nutrition. Leah is a born and raised Vermonter. She met her husband while attending UVM and they are grateful to be raising their two children here in South Burlington.

Kristen Bird, R.N., F.N.P, I.B.C.L.C.

Kristen moved to Vermont from Pennsylvania when she was in high school. Kristen attended college in Greenville, SC and received her nursing degree there in 2007.  Kristen worked as an RN for nearly 6 years on the Mother/Baby unit at Fletcher Allen. In 2011, she completed her degree as a family nurse practitioner at Indiana State University.  She joined Timber Lane Pediatrics in 2012. Kristen is a board-certified lactation consultant and enjoys using her skills to help breastfeeding moms both at Timber Lane and in the community. She and her husband David volunteer at their church and enjoy working with the youth group there. Kristen loves all of pediatrics but is especially interested in breastfeeding, newborn care, and adolescent health. She loves to spend her free time with her husband, 3 children, and Shih Tzu, Teddy, and enjoys hiking, kayaking and spending time with friends.

Courtney Walker, F.N.P.

Courtney started practicing as a Family Nurse Practitioner in 2014. She has a background in family medicine with a focus on health promotion and holistic wellbeing. She values collaboration with her patients and their families to promote joint clinical decision-making. Her nursing career began in 2008 as a Registered Nurse and a Lactation Consultant (IBCLC) on the Mother-Baby Unit at the University of Vermont Medical Center. She is very excited to joint Timber Lane Pediatrics and hopes to focus her practice in pediatric medicine and lactation with this new transition. Courtney lives in Essex with her family and you may find her on the mountain snowboarding or trying out a new vegetarian recipe!

Our Locations

Timber Lane Pediatrics South Burlington

51 Timber Lane
South Burlington, VT 05403

Phone: (802) 864-0521
Fax: (802) 735-9621

Office Hours by Appointment
Monday - Friday 8:30 AM - 5:00 PM
Saturday 8:30 AM - 12:00 PM
Sunday Closed

Timber Lane Pediatrics Burlington

Office location:
1127 North Avenue, Suite 1
Burlington, VT 05408

Mailing address:
PO Box 3057
Burlington, VT 05408

Phone: (802) 846-8100
Fax: (802) 735-9337

Office Hours by Appointment
Monday - Friday 8:30 AM - 5:00 PM
Closed Saturday and Sunday

Timber Lane Pediatrics Milton 

11 Haydenberry Drive, Suite 103
Milton, VT 05468

Phone: (802) 893-1200
Fax: (802) 735-9608

Office Hours by Appointment
Monday - Friday 8:30 AM - 5:00 PM
Closed Saturday and Sunday