Alright, it's unlikely she'd go in public around everyone in a jammie set like that, but it's entirely possible she would've stolen one to wear in her dorm room.

She notices the reaction, and takes half a second to decide how to respond, aggressive and defensive or just let it roll off.

"Well, it's space marines or it's letting alien's destroy anyone and everyone in their way on their mission to wipe out all of humanity. So. And that's not even counting the people trying to kill fellow humans just to fuck the universe over." She shrugs, like it's no biggie.