She expected a more suspicious reaction, frankly, so his concern (or confusion, or even both) comes as a surprise. It takes her a second to respond, and first she addresses his acceptance of her offer.

"All right." A nod, and now— "Yes, I'm fine. It's more comfortable, and..." And there's less people to worry about, with most of them staying inside the giant tree. Animals, no matter how large, are far easier to deal with than a human. She's learned that the hard way and will have to unlearn it with just as much difficulty. She may have had a bed to sleep in for most of her life and sometimes she misses it, but she's gotten used to the dirt and leaves, perhaps too easily.

"And it's cooler out there." A good enough substitute for her true reasons, and not a lie either. "I know some homes are still vacant, but the others can have them. I don't think I could be as fortunate as you and have one all to myself." And even then there would still be neighbors to worry about. She'd rather not.

She tilts her head a bit as she watches him. "You don't have to worry about it. I'm sleeping well."