His eyebrows furrow at that and he stares at her for a long moment, then shakes his head. And then it dawns on him, and his eyes widen just slightly. "Wait. Dahlia Martin?" Lydia's sister. Her sister who had died around the same time his mom had. He'd been to absorbed by that grief to really remember that Lydia had lost someone close to her, too. Not that he and Lydia really talked when they were younger.
Stiles rubs a hand over his face, then motions for her to sit down at the table, which is strewn with Styrofoam cups and books, and a wicked looking knife.