She might understand but there's no way she can empathize, just like he might understand about her patchwork family if she were to explain but he couldn't empathize there, in return. They're odd little boats drifting near each other in a very confused sea.

In space.

Severus walks away but over his shoulder, "Oh-eight-four, if you end up out an airlock."

Before he enters the room with that number.