"We call it her zipper," said her mother, Lori Hughes.
It tells Meghan the heart beneath that scar isn't like the hearts of most other 8-year-olds. It reminds her parents of all the nurses and doctors who spent crucial hours to save their daughter's life.
Meghan was born with pulmonary stenosis, a condition in which her heart's valve obstructs blood flow. She spent the first week of her life strapped to machines in the neonatal intensive care unit at the Medical College of Georgia's Children's Medical Center.
Her twin sister, Madison, spent about one month alongside Meghan in the NICU because of a suckling issue but left the hospital without her sister's condition.
During their time in the hospital, nearly a dozen nurses would cradle, monitor and feed the babies.
Eight years later, Lori and Jeff Hughes don't remember the name or face of every nurse who kept their babies alive. Still, they wanted to say "thank you."
So they returned to the lawn of the children's hospital Saturday to do just that.
Children who spent time in the MCG's NICU as babies were reunited with the staff who took care of them through the NICU Baby Come Back Party.
The Red Wagon Society, a volunteer group that supports the children's hospital, organized the three-hour event for the first time in five years.
"The families in our NICU have to stay here for months at a time, and they do become somewhat like a family with the nurses," said event chairwoman Danielle Moores.
The society sent out more than 2,000 invitations for the event, and about 600 families attended, Moores said.
Families strolled the grounds and mingled with about 20 staff members and neonatologists who cared for the babies years ago.
Moores and volunteers set up booths with face painting, sand art, cakewalks and fall-theme games.
As the Hugheses walked from booth to booth, they searched for familiar faces.
By noon, they were without a reunion, but that didn't matter.
"We just want to show our support," Jeff Hughes said. "(MCG nurses) work really hard to take care of the kids, and it shows."
For the 8-year-old girls, gratitude came a different way. The thought of revisiting the hospital moved the twins to write a poem, which they scribbled on scrap paper the night before.
Today Meghan is still in touch with the cardiologist who has monitored her since birth. Dr. Bill Lutin looked over the three heart surgeries Meghan has had, including the one three years ago that put a valve from a cadaver into her heart.
"She'll have to see him again as a teenager to get the valve replaced," Lori said. "It won't grow with her."
But the Hughes sisters are happy and healthy.
It's success stories such as theirs that keep Melanie Jewett and other nurses returning to the NICU every day.
"It's exciting to see the care we give actually makes a difference," Jewett said.
Jewett and the rest of the staff spend their days giving total bedside care to babies with respiratory distress, underdeveloped lungs and intestinal issues.
They spend hours monitoring feeding tubes and cradling babies in rocking chairs.
About 100 neonatal nurses care for children in the 36-bed facility, according to the hospital's Web site.
Despite the heartache and worry Jewett sees every day, there is always a reward.
"Especially ones that start out very sick; it's neat to see their progression," Jewett said. "It's just very special and very rewarding."