Like many mothers, Irene couldn’t quite believe her children were adults. In her eyes, they were just little girls in grown-up dresses (or ripped jeans, in Carmen’s case). She remembered Sofia trying to get Carmen to behave for five minutes so they could get an ice cream, one holiday down in Ayr. And the queue stretched out of the Italian gelato shop even as more and more people came away with their cones and sandwiches, and Carmen became more and more frantic, despite Sofia trying to calm her down, until the little girl got so upset she had lashed out and knocked another child’s ice cream over. It had been an entire catastrophe. Irene had bought the other child a new ice cream, whereupon his sibling had started to kick off, and then she said Carmen couldn’t have one for yelling, whereupon Sofia had stared at her own ice cream and offered Carmen “a lick . . . No, Mum, she’s taking all of it! She’s taking all of it!” And that had more or less been the end of their day out.

But they were sisters. Sisters always came through in the end, didn’t they? It had been so hard watching Sofia fly through school. Carmen had been such a little reader, but by the time she got to school she couldn’t bear to be compared with her brilliant sibling and fell further and further behind, almost, it felt, on purpose.

“Don’t call them,” Rod, her husband, had said, reading her thoughts as usual. “Let them get on with it. They’ll sort it out.”

Irene had lifted her hands to show she wasn’t already on the phone. “All right, all right.”

“HEY!” SAID SOFIA, flinging open the door with her widest smile.

Carmen, for once, was almost speechless. “Look,” she said. “Oh my God. Look at your house!”

Sofia smiled more naturally this time. She liked people loving the house as much as she did. “Come inside; it’s freezing,” she said.

“But I just want to . . . I mean, this is like something out of a storybook. God. Are you just, like, happy all the time?”

There was a wistful tone to Carmen’s voice, but she genuinely meant it. It was like a doll’s house come to life. She couldn’t even be jealous; it was something so lovely and far out of reach. It would be like being jealous of Amal Clooney.

Sofia smiled. “Come in, will you.”