Can Jon Trust Stephanie?

Jon started to walk away, but Stephanie grabbed his arm before he could. "Hey, what about the stone? Did you bring it?" she asked. He paused, fingering the stone in his pocket. Should he tell her "yes"? Apparently, she thought they were friends and therefore had new memories of using the wishing stone with him. But he didn't really know anything about her. She was almost a stranger. Could he trust a stranger with something as powerful as the stone? On the other hand, if she thought they were friends, didn't that make her trustworthy? Jon thought for a few more seconds, then said ...