What will an 11 year old child do if she's still scared of ghosts and being afraid of being alone?

She is 11 yeaRS old but she's still afraid of ghosts. When she wants to go downstairs at our house to play games, she's too scared because she's alone and there's no one else there and she thinks about ghosts wandering around the house. she always says to her parents to go with her but her parents said that shes old now and they are too busy to come with her. what is she gonna do to forget about those things?