It's a force of habit. Ever since he was taken from Kenari, whenever Cassian sees a woman who could be his sister he tries to get close enough to see if she is or not. Slight build, dark hair, big dark eyes. Jessica is a candidate, at least. Twenty years of disappointment hasn't made him lose hope that maybe, this time, it'll be her. And that he'll know, somehow.

Would she even recognize him? What would she look like, now? He ponders this as he sips from his own mug.

Wait. Did he say something? "Um, no?" He smiles slightly. "Do you want me to?" Now that she's talking to him, he's sure she's not his sister.