"We were devastated," Aimee Fellows tells PEOPLE of her daughter's brain tumor diagnosis

Credit: KC Cohen, Dana-Farber/Boston Children s

In December 2014, 9-year-old Sophie Fellows had to stop playing violin in a holiday recital because of a headache. The very next day, the young girl from Colchester, Vermont, was diagnosed with a brain tumor.

“We were devastated,” Sophie’s mom, Aimee Fellows, tells PEOPLE of the diagnosis. “We were told that based on her age and location it was likely malignant.”

The night before Sophie’s operation to have her brain tumor removed, her fellow violin students and music teacher carpooled from Vermont to Boston Children’s Hospital to join her in performing the songs she had missed.

“It was a wonderful experience,” Sophie’s doctor, Liliana Goumnerova, Director of Neurosurgery at Dana-Farber/Boston Children s Cancer and Blood Disorders Center, tells PEOPLE of the concert. “It was also somewhat anxiety-provoking because she had a very large brain tumor and here was a child who really looked perfect and we wanted to make sure she ended up being perfect.”

Because of the concert’s impromptu nature, a recording stood in for the group’s piano accompanist.

“After the concert, Dr. Goumnerova came up and said, ‘I could ve played the piano part, I play the piano,’ and then she said we should have a reunion concert next year,” Aimee recalls.

With their daughter headed into brain surgery, Aimee said this suggestion gave her and her husband hope in an extremely uncertain time. In reality, there was no guarantee she would ever be able to play the violin again.

That hope helped them stay strong for their little girl through not one – but two brain surgeries, a collapsed lung and a difficult recovery.

“She was on a breathing tube and a feeding tube and really unresponsive through Christmas day,” Aimee explains. “Her lung had collapsed, she had pneumonia and they tried to take her off of the breathing tube and she couldn t breathe on her own.”

Two weeks after her first surgery, Sophie’s parents received confirmation that the young girl’s tumor was benign. She resumed breathing on her own that same day.

With occupational, speech, music and physical therapies, Sophie began what her mom calls a “rapid recovery,” which included returning to her love of playing violin.

One year to the day after having her brain tumor removed, Sophie returned to the halls of Boston Children’s Hospital to hold a holiday concert for patients. Dr. Goumnerova kept her promise and accompanied her on the piano.

The Dec. 11 concert was broadcast to hundreds of patients at the hospital, providing much-needed hope to families in the same position the Fellows found themselves last year.

“I think it was a wonderful opportunity for them to see that children can come in with a serious illness and a tribute to what can be done,” Dr. Goumnerova said.

Adds Sophie, “It felt really good, I was glad to give hope to others.”