"Ah," says Susan. "So you're cathecting to the what-ifs. Then I suppose you oughtn't shut those thoughts down," though she has no intention of thinking about how things might've been with her family if she'd remembered Narnia before they died - she's content to simply write it off as at least she's alive and not in Aslan's land. "And you ought instead explore your feelings." And she gives him an expectant look.