She's about to apologize for telling him not to worry, in that case, but then she notices him lying back, and she's a little surprised. The floor might be good enough for her if she happens to doze off, but if Sam has the means to get a more comfortable sleep, he should go do that.

Hesitating for a moment, Hermione awkwardly moves to lie besides him, a hand reaching out for his arm. "You don't have to take care of me, you know," she tells him, though given the wry quirk of her lips, even she understands that it isn't as though he's the sort to abandon anyone who looks to be in trouble. "Besides, spending all this time with a sick person just makes it more likely you'll get sick. So either you should take care of yourself, or you have to admit that I'm not as sick as you're making me out to be."