But since the two had cystic fibrosis, it was very risky for them to meet in person. Dalton Prager had an infection called burkholderia cepacia that is highly contagious for people with cystic fibrosis, an infection then-Katie Donovan did not have.
"I told Dalton I'd rather be happy -- like really, really happy -- for five years of my life and die sooner than be mediocre happy and live for 20 years," Katie said. "That was definitely something I had to think about, but when you have those feelings, you just know."
So the couple met in person, and married two years later in 2011, when they were both 20 years old.
Katie Prager ended up contracting the bacteria and the two waited for lung transplants. Both eventually got them and Dalton Prager's transplant was successful, but he discovered he had lymphoma. He successfully fought cancer, but was hospitalized with pneumonia.
Katie Prager had complications following her transplant and it was never successful. There is now nothing more she can do and is currently in hospice care at the couple's home in Kentucky.
She could not see her husband one last time in person before his death, and Dalton Prager's health complications made it impossible for him to fly home from Stl. Louis. Instead, the two were on a video chat together when Dalton Prager died.
"It gave me some of the best years of my life," she told CNN. "I'd rather have five years of being in love and just really completely happy than 20 years of not having anybody."
Dalton Prager's funeral is Wednesday. A GoFundMe page has been set up to help with medical costs for the couple and funeral costs.
According to Prager's obituary, the family asks that contributions be made to the Cystic Fibrosis Foundation or to the Leukemia & Lymphoma Society.