There's more people than bunks and Aya is new and has no friends here and can't very well fight somebody for theirs so she's on the floor. It's cold and she'd better fall asleep before it gets colder or she'll be shivering all night. At the old lady's the mat she had was deep enough that she could lie on her back without her collar digging into her neck; here no such luck so she's on her side, arm under her head.