Amy was on the edge of falling asleep, even if it was a very odd situation. Even accounting for the Winchester element to things. Curled up and being petted set her into a very content and sleepy place. Jo's words jarred her out of that.

"Which isn't? Being dead or being here?" Amy then nudged Sam's hand with her nose at Jo holding whatever her necklace held. Something that she did herself plenty of times with the little stars and moon when she needed reassurance. Maybe it was time to face being human again. Recovering enough energy to keep herself to her normal appearance.