Morgan Dixon always had a plan, and it never involved staying in Cincinnati. Even in high school, she thought far beyond her hometown, writing officials in developing countries as part of the school’s Amnesty International club and urging them to stop violating human rights. “You have the world to explore!” her parents wrote next to her picture in her 2002 yearbook. “Enjoy Life!”

So Ms. Dixon explored — China, Costa Rica, Guatemala, Ghana, Burundi. She met her future fiancé, Craig Spencer, in a language immersion course in Henan Province in China in 2006 or 2007. He shared her passion for helping others less fortunate.

This week, after learning that Dr. Spencer had brought Ebola home to New York from Guinea, Ms. Dixon also checked herself into the hospital and was put in quarantine as a precaution. She returned home Saturday evening and will continue her quarantine there.

Ms. Dixon appeared to take the initial news with grace.

“She literally was like, ‘This is amazing, being in a privileged position in a well-resourced country,’ ” said a longtime friend, Shalva Wise, who said she spoke to Ms. Dixon by phone on Friday afternoon. “She was also thinking about the folks over there who he left behind.”