It occurs to Skellig that the idea and concept of taking a nap is likely completely foreign and forbidden to her.

"There is nothing wrong with that."

Pausing to unlock the door to their room, he steps aside to let her enter first. (Though he does "listen" quickly to ensure it is as they left it.)

"And if you need to sleep, it will give you time for your body to work on healing itself... so you will still be working. Just on yourself."