When Ms. Curtis responded to their ad, they told her that it probably wouldn’t be a good fit, as they keep a kosher kitchen (no ham sandwiches) and are Sabbath-observant (no laptop in the living room on Friday nights). She surprised them by being up for the challenge of the house rules, though it took her a while to get the hang of them.

A former roommate gave her two books on Jewish dietary laws, she said. “I also had the rabbi’s number and would call him from the grocery store and take photos of kosher symbols and text for approval.”

“We threw out a lot of dishes,” Ms. Waldman said. A system of Post-it notes eventually did the trick, and during Passover the three other roommates covered the higher cost of groceries.

Ms. Curtis, who now lives in Florida, compared living in the apartment to her time in the Peace Corps in Mali.

“Even though you’re living in a culture that’s somewhat alien to you, you’re part of the family and part of a tradition,” she said over the phone. “I didn’t know when I moved in that it would become one of the best apartments I ever lived in. In the U.S., it’s considered shameful if you live with roommates, like you haven’t been successful. But it’s nice to come home to people. The two years that I lived there, I had academic difficulties, personal difficulties, health problems. It felt good to know that you weren’t by yourself.”