Crippen had been hospitalized at Nebraska Medicine for more than a month while recovering from COVID-19 and a broken arm sustained in a fall resulting from the illness.
Boro said she used a white board to communicate with Crippen, who is hard of hearing, and they quickly confirmed they shared the same father, Wendall Huffman.
Crippen and Boro, who have different mothers, were raised in separate homes, and Boro had ended up in the foster care system when she was less than 6 months old, before eventually being adopted.
Crippen was the first of Huffman's 10 children with three different mothers, and Boro was the youngest.
The women said they had been searching for one another for years and knew each other's names, but were never able to find contact information. Crippen said she now considers her brush with coronavirus to be "a blessing."
"I am the happiest person in the world," Crippen told the Washington Post. "I cannot believe I finally found my sister."