Jack approaches. He's seen worse than a demon-lady. He doesn't get too close though, either, because he's also not stupid. He announces his presence by waving the water bottle in his hand in her general direction, and smiling amiably, as if he doesn't even see the wings and horns and red skin.

Look, his best friend is a tree-man. He can handle a demon-looking person.

"Hello! I have water? It will probably taste very much like plastic, but it is probably good to stay hydrated out here."