Once I’m dried off and dressed, I find her waiting for me downstairs in the living room, playing around on her phone next to her mother, doing a good job of pretending to look irritated. But the moment she looks up and our eyes meet, that expression falters for a brief moment, and I see the excitement there.

Fortunately, when her mom looks up, she quickly glances back down at her phone.

“All set, sis?” I ask.

“Yeah,” she replies, sounding annoyed as she lifts herself from the couch.

“Don’t sound so miserable, you two,” Susan says. “Get to know each other. You just might like each other! It took...