In addition to the main lost girls, there could be side characters such as wise old men or women who offer advice to the rescuers or the lost girls themselves. There might also be animals in the story. If it's set in a forest, for example, friendly animals could help the girls, or dangerous animals could add to the challenges they face.
It could be about girls who are lost, perhaps physically lost in a place like a forest or a big city. Maybe they are lost in a more metaphorical sense, like lost in life, not knowing their purpose or direction.