She started to stir, and sleepily blinked her eyes open. Her mind was still muddled with sleep so the nakedness got a quizzical, "hmmm?" Naked but very warm, why? Oh, naked man here.

...Naked man???

She did briefly startle, but then relaxed when she noticed Will. "Oh, hi... you're here." Which means they... oh! oh wow. Right. But she didn't regret this, it just seemed natural with him really.