The sun "rises" in the east and "sets" in the west. Since Erin is at the Atlantic Ocean, she would see the rising sun as she looks out at the ocean in the morning. Since most beach hotels face the ocean, it makes sense that the back of the hotel is facing a westerly direction. The earth revolves around its axis in an easterly direction. As the earth revolve to the east, it makes the sun look as though it is moving west.