She agrees with him, she won't stop looking or coming out here with him. It's why she stayed.

"Then we'll keep looking. They still could have landed in the jungle," she offers, not wanting to give him a reason to give up.

"Come on. I'm not in a rush and we have time before we need to turn back. We can keep going, be sure." She knows how important this is to him, no matter how convinced she is that they're gone.