VIRGINIA BEACH, Va. (WVEC)--Abby Furco and Sarah Ronstock have known each other for years.
The two met at a summer camp in 2013.
Despite the age difference---Abby was seven years old and Sarah was 25---they had a lot in common.
Both would end up fighting rare forms of Leukemia that relapsed, and both needed transplants to get better.
But it wasn't until this year that Abby, now 10, showed Sarah how strong their friendship really is.
"I recently said she's the first miracle I've ever witnessed,” Sarah said. “And it's just clear how much that's true."
This summer, Sarah asked Abby to be the flower girl at her wedding.
They were both excited with the October wedding just a few months away.
But following a bone marrow transplant, doctors gave a Abby a terrifying prognosis.
She was given 48 hours to live.
"That week was very hard for me,” Sarah said. “Just because you want to be positive but you also want to be realistic."
48 hours turned into weeks, and then weeks turned into months.
Abby wasn't only surviving, she was thriving, driven by a seemingly simple goal that meant the world to the 10-year-old.
"Helping Sarah have the best wedding she could ever have,” Abby said.
On October 29th, Abby walked down the aisle as Sarah's flower girl.
"It speaks to the epitome of her soul,” Sarah said. “It speaks to her drive and fight within."
Sarah and Abby are active in St. Baldrick's Foundation, the largest private fund for childhood cancer research grants.
They were both treated with clinical trials supported by the Foundation and are living proof of the difference research can make.
Through the Foundation, Sarah also served as one of the five 2012 Ambassadors, and shaved her head – with Abby’s help – at one of St. Baldrick’s signature head-shaving events this past March.