South Burlington Office :

Burlington Office :
(802) 846-8100

Milton Office :

South Burlington Office

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.

Thomas Bolduc, M.D., F.A.A.P.

Dr. Bolduc, a native of Portland, Maine, met his wife at the University of Vermont College of Medicine.  After finishing both of their pediatric residencies at UVM, they worked as pediatricians for the US Navy in Yokosuka, Japan and Bremerton, Washington.  After leaving the Navy, they spent the next ten years sharing a pediatric practice in Walla Walla, Washington while raising their two sons and exploring the western U.S.  In 2013, after 14 years away, they decided it was time to come “home” to Vermont.  Dr. Bolduc enjoys hiking, snowshoeing, flat-water kayaking, cooking, and time in his hammock.

Elizabeth Hunt, M.D., F.A.A.P., I.B.C.L.C.

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.   

Barbara Kennedy, M.D., F.A.A.P.

Dr. Barbara Kennedy, a native of Madison, Wisconsin, and her husband, an ER physician, graduated from the Medical College of Wisconsin and did their residencies in Rochester, NY.  They worked in Nashville, TN for several years before moving to the San Francisco Bay area, where Dr. Kennedy worked for the Palo Alto Medical Center while her husband got his MBA at Stanford.  In 1993 they saw the light and moved to Shelburne, VT with their 4 daughters.  Dr. Kennedy enjoys caring for all pediatric patients from birth through college.  Her area of special interest is wilderness and travel medicine.  She has authored several medical textbook chapters and written pediatric guides to wilderness and foreign travel.  She and her husband have traveled with their daughters to six of the seven continents.  Dr Kennedy also enjoys running, biking, and skiing and is a proud member of the nationally competitive “Vintage,” a women’s 50 and over ice hockey team. 

Kari McKinley, C.P.N.P.

Kari McKinley grew up in the Adirondacks in upstate New York. From there she traveled north to Montreal, Canada where she earned a Bachelor’s degree in Biology from McGill University, with a focus in laboratory research in developmental genetics. Upon completion of her program, Kari moved back to the US to Burlington, VT where she spent a few years working as a medical assistant at Timber Lane Pediatrics. It was here she learned that while she loved fundamental science, it was working with children and their families that gave her the most fulfillment. Kari went on to complete an accelerated RN to Master of Science in Nursing program at Yale University in New Haven, CT. She returned to Vermont in 2013 to work as a Pediatric Nurse Practitioner, first in the Connecticut River Valley and then in 2015, when she rejoined Timber Lane Pediatrics. When not at work she can be found doing any number of activities including telemark skiing, knitting, road biking, dancing, traveling, taking outdoor adventures with her fiancé and dog, and generally enjoying time with family and friends.

Madeline Mann, F.N.P.

Madeline joined Timber Lane after over 26 years of pediatric practice. She graduated from Tufts University with a BS in child Development and Psychology. After working at Children’s Hospital Boston, she went on to receive her RN and MSN as a family nurse practitioner at Yale University in 1986. She has had the privilege of working in partnership with children and their families ever since. Madeline enjoys children of all ages, with special interests in prevention, adolescence, and behavioral medicine. She also loves spending time with her family, traveling, and just about anything outdoors – running, skiing, biking, hiking and working in her gardens.

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.

Rebecca Nagle, P.N.P., I.B.C.L.C.

Rebecca has been a registered nurse for twenty years and has been a pediatric nurse practitioner since 1999. She graduated with a nursing degree from the University of Vermont in 1991 and from the University of California, San Francisco in 1999 with a Master’s Degree in Child Health and a Pediatric Nurse Practitioner Certificate.  Rebecca enjoys caring for all pediatric patients, birth through college, and has special interests in lactation, newborns and adolescents.  Rebecca has traveled and worked in international health care for 16 years, focusing on child and maternal health.  She works part-time and spends her non-working hours with her husband and three children. They enjoy traveling, skiing, surfing, mountain biking and playing outdoors.

Nurse Manager, Care Coordinator

Jan Rahelich, RN

Office Manager

Robyn Lefebvre



Timber Lane Pediatrics South Burlington
51 Timber Lane
South Burlington, VT 05403-5201
Phone: (802) 864-0521
Fax: (802) 735-9621

Monday - Friday 8:30 AM - 5:30 PM
Saturday and Sunday 8:30 AM - 12:00 PM*
*Saturday and Sunday appointments for acute illness and newborn visits only

Timber Lane Pediatrics Burlington

Office location:
1127 North Avenue, Suite 41
Burlington, VT 05408

Mailing address:
PO Box 3057
Burlington, VT 05408

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

Monday 8:30AM - 5:30 PM
Tuesday - 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

Monday - Friday 8:30 AM - 5:00 PM*
Closed Saturday and Sunday
*Provider appointments now available all day Wednesdays